1
|
Velluire-Pellat Z, Maréchal E, Moulonguet N, Saïz G, Ménard GC, Kozlov S, Couëdo F, Amari P, Medous C, Paris J, Hostein R, Lesueur J, Feuillet-Palma C, Bergeal N. Author Correction: Hybrid quantum systems with high-T c superconducting resonators. Sci Rep 2023; 13:17407. [PMID: 37833386 PMCID: PMC10575915 DOI: 10.1038/s41598-023-44720-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023] Open
Affiliation(s)
- Z Velluire-Pellat
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - E Maréchal
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - N Moulonguet
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - G Saïz
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - G C Ménard
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - S Kozlov
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - F Couëdo
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
- Laboratoire National de Métrologie et d'Essais (LNE), 29 Avenue Roger Hennequin, 78197, Trappes, France
| | - P Amari
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - C Medous
- CNRS, Institut Fourier, Université Grenoble Alpes, 38000, Grenoble, France
- Université Grenoble Alpes, INRIA, 38000, Grenoble, France
| | - J Paris
- My Cryo Firm, 20 Villa des Carrières, 94120, Fontenay-sous-Bois, France
| | - R Hostein
- My Cryo Firm, 20 Villa des Carrières, 94120, Fontenay-sous-Bois, France
| | - J Lesueur
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France.
| |
Collapse
|
2
|
Velluire-Pellat Z, Maréchal E, Moulonguet N, Saïz G, Ménard GC, Kozlov S, Couëdo F, Amari P, Medous C, Paris J, Hostein R, Lesueur J, Feuillet-Palma C, Bergeal N. Hybrid quantum systems with high-T[Formula: see text] superconducting resonators. Sci Rep 2023; 13:14366. [PMID: 37658090 PMCID: PMC10474070 DOI: 10.1038/s41598-023-41472-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/27/2023] [Indexed: 09/03/2023] Open
Abstract
Superconducting microwave resonators are crucial elements of microwave circuits, offering a wide range of potential applications in modern science and technology. While conventional low-T[Formula: see text] superconductors are mainly employed, high-T[Formula: see text] cuprates could offer enhanced temperature and magnetic field operating ranges. Here, we report the realization of [Formula: see text] superconducting coplanar waveguide resonators, and demonstrate a continuous evolution from a lossy undercoupled regime, to a lossless overcoupled regime by adjusting the device geometry, in good agreement with circuit model theory. A high-quality factor resonator was then used to perform electron spin resonance measurements on a molecular spin ensemble across a temperature range spanning two decades. We observe spin-cavity hybridization indicating coherent coupling between the microwave field and the spins in a highly cooperative regime. The temperature dependence of the Rabi splitting and the spin relaxation time point toward an antiferromagnetic coupling of the spins below 2 K. Our findings indicate that high-Tc superconducting resonators hold great promise for the development of functional circuits. Additionally, they suggest novel approaches for achieving hybrid quantum systems based on high-T[Formula: see text] superconductors and for conducting electron spin resonance measurements over a wide range of magnetic fields and temperatures.
Collapse
Affiliation(s)
- Z. Velluire-Pellat
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - E. Maréchal
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - N. Moulonguet
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - G. Saïz
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - G. C. Ménard
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - S. Kozlov
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - F. Couëdo
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
- Laboratoire National de Métrologie et d’Essais (LNE), 29 Avenue Roger Hennequin, 78197 Trappes, France
| | - P. Amari
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - C. Medous
- CNRS, Institut Fourier, Université Grenoble Alpes, 38000 Grenoble, France
- Université Grenoble Alpes, INRIA, 38000 Grenoble, France
| | - J. Paris
- My Cryo Firm, 20 Villa des Carrières, 94120 Fontenay-sous-Bois, France
| | - R. Hostein
- My Cryo Firm, 20 Villa des Carrières, 94120 Fontenay-sous-Bois, France
| | - J. Lesueur
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - C. Feuillet-Palma
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - N. Bergeal
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| |
Collapse
|
3
|
Varotto S, Johansson A, Göbel B, Vicente-Arche LM, Mallik S, Bréhin J, Salazar R, Bertran F, Fèvre PL, Bergeal N, Rault J, Mertig I, Bibes M. Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO 3 interfaces. Nat Commun 2022; 13:6165. [PMID: 36257940 PMCID: PMC9579156 DOI: 10.1038/s41467-022-33621-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/23/2022] [Indexed: 11/25/2022] Open
Abstract
Rashba interfaces have emerged as promising platforms for spin-charge interconversion through the direct and inverse Edelstein effects. Notably, oxide-based two-dimensional electron gases display a large and gate-tunable conversion efficiency, as determined by transport measurements. However, a direct visualization of the Rashba-split bands in oxide two-dimensional electron gases is lacking, which hampers an advanced understanding of their rich spin-orbit physics. Here, we investigate KTaO3 two-dimensional electron gases and evidence their Rashba-split bands using angle resolved photoemission spectroscopy. Fitting the bands with a tight-binding Hamiltonian, we extract the effective Rashba coefficient and bring insight into the complex multiorbital nature of the band structure. Our calculations reveal unconventional spin and orbital textures, showing compensation effects from quasi-degenerate band pairs which strongly depend on in-plane anisotropy. We compute the band-resolved spin and orbital Edelstein effects, and predict interconversion efficiencies exceeding those of other oxide two-dimensional electron gases. Finally, we suggest design rules for Rashba systems to optimize spin-charge interconversion performance. Visualization of the Rashbasplit bands in oxide two-dimensional electron gases is lacking, which hampers understanding of their rich spin-orbit physics. Here, the authors investigate KTaO3 two dimensional electron gases and their Rashba-split bands.
Collapse
Affiliation(s)
- Sara Varotto
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Annika Johansson
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany.
| | - Börge Göbel
- Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, 06099, Halle, Germany
| | - Luis M Vicente-Arche
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Srijani Mallik
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Julien Bréhin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Raphaël Salazar
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - François Bertran
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Patrick Le Fèvre
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, 75005, Paris, France
| | - Julien Rault
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Ingrid Mertig
- Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, 06099, Halle, Germany
| | - Manuel Bibes
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
| |
Collapse
|
4
|
Mallik S, Ménard GC, Saïz G, Witt H, Lesueur J, Gloter A, Benfatto L, Bibes M, Bergeal N. Superfluid stiffness of a KTaO 3-based two-dimensional electron gas. Nat Commun 2022; 13:4625. [PMID: 35941153 PMCID: PMC9360446 DOI: 10.1038/s41467-022-32242-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/21/2022] [Indexed: 11/09/2022] Open
Abstract
After almost twenty years of intense work on the celebrated LaAlO3/SrTiO3system, the recent discovery of a superconducting two-dimensional electron gas (2-DEG) in (111)-oriented KTaO3-based heterostructures injects new momentum to the field of oxides interface. However, while both interfaces share common properties, experiments also suggest important differences between the two systems. Here, we report gate tunable superconductivity in 2-DEGs generated at the surface of a (111)-oriented KTaO3 crystal by the simple sputtering of a thin Al layer. We extract the superfluid stiffness of the 2-DEGs and show that its temperature dependence is consistent with a node-less superconducting order parameter having a gap value larger than expected within a simple BCS weak-coupling limit model. The superconducting transition follows the Berezinskii-Kosterlitz-Thouless scenario, which was not reported on SrTiO3-based interfaces. Our finding offers innovative perspectives for fundamental science but also for device applications in a variety of fields such as spin-orbitronics and topological electronics.
Collapse
Affiliation(s)
- S Mallik
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 Avenue Augustin Fresnel, 91767, Palaiseau, France
| | - G C Ménard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, Paris, France
| | - G Saïz
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, Paris, France
| | - H Witt
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 Avenue Augustin Fresnel, 91767, Palaiseau, France.,Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, Paris, France
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, Paris, France
| | - A Gloter
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS UMR 8502, 91405, Orsay, France
| | - L Benfatto
- Department of Physics and ISC-CNR, Sapienza University of Rome, Rome, Italy
| | - M Bibes
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 Avenue Augustin Fresnel, 91767, Palaiseau, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, Paris, France.
| |
Collapse
|
5
|
Sanchez-Manzano D, Mesoraca S, Cuellar FA, Cabero M, Rouco V, Orfila G, Palermo X, Balan A, Marcano L, Sander A, Rocci M, Garcia-Barriocanal J, Gallego F, Tornos J, Rivera A, Mompean F, Garcia-Hernandez M, Gonzalez-Calbet JM, Leon C, Valencia S, Feuillet-Palma C, Bergeal N, Buzdin AI, Lesueur J, Villegas JE, Santamaria J. Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet. Nat Mater 2022; 21:188-194. [PMID: 34857910 DOI: 10.1038/s41563-021-01162-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La0.7Sr0.3MnO3 combined with the superconducting cuprate YBa2Cu3O7. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.
Collapse
Affiliation(s)
- D Sanchez-Manzano
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - S Mesoraca
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - F A Cuellar
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - M Cabero
- IMDEA Nanoscience Institute, Universidad Autonoma, Cantoblanco, Spain
- Centro Nacional de Microscopia Electronica, Universidad Complutense, Madrid, Spain
| | - V Rouco
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - G Orfila
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - X Palermo
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - A Balan
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - L Marcano
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - A Sander
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - M Rocci
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
- Instituto Nanoscienze, Consiglio Thales Alenia Space Italia, L'Aquila, Italy
| | | | - F Gallego
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - J Tornos
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - A Rivera
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - F Mompean
- Instituto de Ciencia de Materiales de Madrid (ICMM, CSIC), Cantoblanco, Spain
- Laboratorio de Heteroestructuras con Aplicación en Spintrónica, Unidad Asociada (UCM-CSIC), Madrid, Spain
| | - M Garcia-Hernandez
- Instituto de Ciencia de Materiales de Madrid (ICMM, CSIC), Cantoblanco, Spain
- Laboratorio de Heteroestructuras con Aplicación en Spintrónica, Unidad Asociada (UCM-CSIC), Madrid, Spain
| | - J M Gonzalez-Calbet
- Centro Nacional de Microscopia Electronica, Universidad Complutense, Madrid, Spain
- Departamento Química Inorgánica, Facultad de Química, Universidad Complutense, Madrid, Spain
| | - C Leon
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - S Valencia
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, CNRS, PSL Research University, Sorbonne University, Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, CNRS, PSL Research University, Sorbonne University, Paris, France
| | - A I Buzdin
- LOMA, CNRS, Université Bordeaux, Talence, France
- Digital Biodesign and Personalized Healthcare, Sechenov First Moscow State Medical University, Moscow, Russia
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, CNRS, PSL Research University, Sorbonne University, Paris, France
| | - Javier E Villegas
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, France.
| | - J Santamaria
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain.
- Laboratorio de Heteroestructuras con Aplicación en Spintrónica, Unidad Asociada (UCM-CSIC), Madrid, Spain.
| |
Collapse
|
6
|
Mallik S, Ménard GC, Saïz G, Gilmutdinov I, Vignolles D, Proust C, Gloter A, Bergeal N, Gabay M, Bibes M. From Low-Field Sondheimer Oscillations to High-Field Very Large and Linear Magnetoresistance in a SrTiO 3-Based Two-Dimensional Electron Gas. Nano Lett 2022; 22:65-72. [PMID: 34914397 DOI: 10.1021/acs.nanolett.1c03198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Quantum materials harbor a cornucopia of exotic transport phenomena challenging our understanding of condensed matter. Among these, a giant, nonsaturating linear magnetoresistance (MR) has been reported in various systems, from Weyl semimetals to topological insulators. Its origin is often ascribed to unusual band structure effects, but it may also be caused by extrinsic sample disorder. Here, we report a very large linear MR in a SrTiO3 two-dimensional electron gas and, by combining transport measurements with electron spectromicroscopy, show that it is caused by nanoscale inhomogeneities that are self-organized during sample growth. Our data also reveal semiclassical Sondheimer oscillations arising from interferences between helicoidal electron trajectories, from which we determine the 2DEG thickness. Our results bring insight into the origin of linear MR in quantum materials, expand the range of functionalities of oxide 2DEGs, and suggest exciting routes to explore the interaction of linear MR with features like Rashba spin-orbit coupling.
Collapse
Affiliation(s)
- Srijani Mallik
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 Avenue Augustin Fresnel, 91767 Palaiseau, France
| | - Gerbold C Ménard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, 75005 Paris, France
| | - Guilhem Saïz
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, 75005 Paris, France
| | - Ildar Gilmutdinov
- LNCMI-EMFL, CNRS, Université Grenoble Alpes, INSA-T, UPS, 31400 Toulouse, France
| | - David Vignolles
- LNCMI-EMFL, CNRS, Université Grenoble Alpes, INSA-T, UPS, 31400 Toulouse, France
| | - Cyril Proust
- LNCMI-EMFL, CNRS, Université Grenoble Alpes, INSA-T, UPS, 31400 Toulouse, France
| | - Alexandre Gloter
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS UMR 8502, 91405 Orsay, France
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université, 75005 Paris, France
| | - Marc Gabay
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS UMR 8502, 91405 Orsay, France
| | - Manuel Bibes
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 Avenue Augustin Fresnel, 91767 Palaiseau, France
| |
Collapse
|
7
|
Vicente-Arche LM, Bréhin J, Varotto S, Cosset-Cheneau M, Mallik S, Salazar R, Noël P, Vaz DC, Trier F, Bhattacharya S, Sander A, Le Fèvre P, Bertran F, Saiz G, Ménard G, Bergeal N, Barthélémy A, Li H, Lin CC, Nikonov DE, Young IA, Rault JE, Vila L, Attané JP, Bibes M. Spin-Charge Interconversion in KTaO 3 2D Electron Gases. Adv Mater 2021; 33:e2102102. [PMID: 34499763 DOI: 10.1002/adma.202102102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Oxide interfaces exhibit a broad range of physical effects stemming from broken inversion symmetry. In particular, they can display non-reciprocal phenomena when time reversal symmetry is also broken, e.g., by the application of a magnetic field. Examples include the direct and inverse Edelstein effects (DEE, IEE) that allow the interconversion between spin currents and charge currents. The DEE and IEE have been investigated in interfaces based on the perovskite SrTiO3 (STO), albeit in separate studies focusing on one or the other. The demonstration of these effects remains mostly elusive in other oxide interface systems despite their blossoming in the last decade. Here, the observation of both the DEE and IEE in a new interfacial two-dimensional electron gas (2DEG) based on the perovskite oxide KTaO3 is reported. 2DEGs are generated by the simple deposition of Al metal onto KTaO3 single crystals, characterized by angle-resolved photoemission spectroscopy and magnetotransport, and shown to display the DEE through unidirectional magnetoresistance and the IEE by spin-pumping experiments. Their spin-charge interconversion efficiency is then compared with that of STO-based interfaces, related to the 2DEG electronic structure, and perspectives are given for the implementation of KTaO3 2DEGs into spin-orbitronic devices is compared.
Collapse
Affiliation(s)
- Luis M Vicente-Arche
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Julien Bréhin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Sara Varotto
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Maxen Cosset-Cheneau
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, Grenoble, 38000, France
| | - Srijani Mallik
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Raphaël Salazar
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Paul Noël
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, Grenoble, 38000, France
| | - Diogo C Vaz
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Felix Trier
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Suvam Bhattacharya
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Anke Sander
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Patrick Le Fèvre
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - François Bertran
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Guilhem Saiz
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, 75231, France
| | - Gerbold Ménard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, 75231, France
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, Sorbonne Université, Paris, 75231, France
| | - Agnès Barthélémy
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| | - Hai Li
- Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Chia-Ching Lin
- Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | | | - Ian A Young
- Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Julien E Rault
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette Cedex, 91192, France
| | - Laurent Vila
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, Grenoble, 38000, France
| | - Jean-Philippe Attané
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, Grenoble, 38000, France
| | - Manuel Bibes
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 1 avenue Augustin Fresnel, Palaiseau, 91767, France
| |
Collapse
|
8
|
Couëdo F, Amari P, Feuillet-Palma C, Ulysse C, Srivastava YK, Singh R, Bergeal N, Lesueur J. Dynamic properties of high-T c superconducting nano-junctions made with a focused helium ion beam. Sci Rep 2020; 10:10256. [PMID: 32581302 PMCID: PMC7314811 DOI: 10.1038/s41598-020-66882-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/28/2020] [Indexed: 11/09/2022] Open
Abstract
The Josephson junction (JJ) is the corner stone of superconducting electronics and quantum information processing. While the technology for fabricating low Tc JJ is mature and delivers quantum circuits able to reach the "quantum supremacy", the fabrication of reproducible and low-noise high-Tc JJ is still a challenge to be taken up. Here we report on noise properties at RF frequencies of recently introduced high-Tc Josephson nano-junctions fabricated by mean of a Helium ion beam focused at sub-nanometer scale on a YBa2Cu3O7 thin film. We show that their current-voltage characteristics follow the standard Resistively-Shunted-Junction (RSJ) circuit model, and that their characteristic frequency fc = (2e/h)IcRn reaches ~300 GHz at low temperature. Using the "detector response" method, we evidence that the Josephson oscillation linewidth is only limited by the thermal noise in the RSJ model for temperature ranging from T ~ 20 K to 75 K. At lower temperature and for the highest He irradiation dose, the shot noise contribution must also be taken into account when approaching the tunneling regime. We conclude that these Josephson nano-junctions present the lowest noise level possible, which makes them very promising for future applications in the microwave and terahertz regimes.
Collapse
Affiliation(s)
- François Couëdo
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI Paris, PSL Research University, UPMC, 75005, Paris, France
- Laboratoire National de Métrologie et d'Essais (LNE), Quantum Electrical Metrology Department, Avenue Roger Hennequin, 78197, Trappes, France
| | - Paul Amari
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI Paris, PSL Research University, UPMC, 75005, Paris, France
| | - Cheryl Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI Paris, PSL Research University, UPMC, 75005, Paris, France
| | - Christian Ulysse
- Centre de Nanosciences et de Nanotechnologie, CNRS, Université Paris Saclay, 91120, Palaiseau, France
| | - Yogesh Kumar Srivastava
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Ranjan Singh
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI Paris, PSL Research University, UPMC, 75005, Paris, France
| | - Jérôme Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI Paris, PSL Research University, UPMC, 75005, Paris, France.
| |
Collapse
|
9
|
Rouco V, Hage RE, Sander A, Grandal J, Seurre K, Palermo X, Briatico J, Collin S, Trastoy J, Bouzehouane K, Buzdin AI, Singh G, Bergeal N, Feuillet-Palma C, Lesueur J, Leon C, Varela M, Santamaría J, Villegas JE. Quasiparticle tunnel electroresistance in superconducting junctions. Nat Commun 2020; 11:658. [PMID: 32005810 PMCID: PMC6994500 DOI: 10.1038/s41467-020-14379-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 12/30/2019] [Indexed: 11/13/2022] Open
Abstract
The term tunnel electroresistance (TER) denotes a fast, non-volatile, reversible resistance switching triggered by voltage pulses in ferroelectric tunnel junctions. It is explained by subtle mechanisms connected to the voltage-induced reversal of the ferroelectric polarization. Here we demonstrate that effects functionally indistinguishable from the TER can be produced in a simpler junction scheme—a direct contact between a metal and an oxide—through a different mechanism: a reversible redox reaction that modifies the oxide’s ground-state. This is shown in junctions based on a cuprate superconductor, whose ground-state is sensitive to the oxygen stoichiometry and can be tracked in operando via changes in the conductance spectra. Furthermore, we find that electrochemistry is the governing mechanism even if a ferroelectric is placed between the metal and the oxide. Finally, we extend the concept of electroresistance to the tunnelling of superconducting quasiparticles, for which the switching effects are much stronger than for normal electrons. Besides providing crucial understanding, our results provide a basis for non-volatile Josephson memory devices. The non-volatile switching of tunnel electroresistance in ferroelectric junctions provides the basis for memory and neuromorphic computing devices. Rouco et al. show tunnel electroresistance in superconductor-based junctions that arises from a redox rather than ferroelectric mechanism and is enhanced by superconductivity.
Collapse
Affiliation(s)
- V Rouco
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.,Grupo de Física de Materiales Complejos, Dpto. Física de Materiales, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - R El Hage
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - A Sander
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - J Grandal
- Grupo de Física de Materiales Complejos, Dpto. Física de Materiales, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - K Seurre
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - X Palermo
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - J Briatico
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - S Collin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - J Trastoy
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - K Bouzehouane
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - A I Buzdin
- Université de Bordeaux, LOMA UMR CNRS 5798, F-33405, Talence, France
| | - G Singh
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, 75005, Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, 75005, Paris, France
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, 75005, Paris, France
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, Université PSL, CNRS, 75005, Paris, France
| | - C Leon
- Grupo de Física de Materiales Complejos, Dpto. Física de Materiales, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - M Varela
- Grupo de Física de Materiales Complejos, Dpto. Física de Materiales, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - J Santamaría
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.,Grupo de Física de Materiales Complejos, Dpto. Física de Materiales, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Javier E Villegas
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
| |
Collapse
|
10
|
Vaz DC, Noël P, Johansson A, Göbel B, Bruno FY, Singh G, McKeown-Walker S, Trier F, Vicente-Arche LM, Sander A, Valencia S, Bruneel P, Vivek M, Gabay M, Bergeal N, Baumberger F, Okuno H, Barthélémy A, Fert A, Vila L, Mertig I, Attané JP, Bibes M. Mapping spin-charge conversion to the band structure in a topological oxide two-dimensional electron gas. Nat Mater 2019; 18:1187-1193. [PMID: 31501554 DOI: 10.1038/s41563-019-0467-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 07/23/2019] [Indexed: 05/23/2023]
Abstract
While spintronics has traditionally relied on ferromagnetic metals as spin generators and detectors, spin-orbitronics exploits the efficient spin-charge interconversion enabled by spin-orbit coupling in non-magnetic systems. Although the Rashba picture of split parabolic bands is often used to interpret such experiments, it fails to explain the largest conversion effects and their relationship with the electronic structure. Here, we demonstrate a very large spin-to-charge conversion effect in an interface-engineered, high-carrier-density SrTiO3 two-dimensional electron gas and map its gate dependence on the band structure. We show that the conversion process is amplified by enhanced Rashba-like splitting due to orbital mixing and in the vicinity of avoided band crossings with topologically non-trivial order. Our results indicate that oxide two-dimensional electron gases are strong candidates for spin-based information readout in new memory and transistor designs. Our results also emphasize the promise of topology as a new ingredient to expand the scope of complex oxides for spintronics.
Collapse
Affiliation(s)
- Diogo C Vaz
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Paul Noël
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France
| | - Annika Johansson
- Max Planck Institute of Microstructure Physics, Halle, Germany
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Börge Göbel
- Max Planck Institute of Microstructure Physics, Halle, Germany
| | - Flavio Y Bruno
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
| | - Gyanendra Singh
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
| | | | - Felix Trier
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Luis M Vicente-Arche
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Anke Sander
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Sergio Valencia
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - Pierre Bruneel
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Manali Vivek
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Marc Gabay
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Nicolas Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
| | - Felix Baumberger
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG-MEM, Grenoble, France
| | - Agnès Barthélémy
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Albert Fert
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Laurent Vila
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France.
| | - Ingrid Mertig
- Max Planck Institute of Microstructure Physics, Halle, Germany
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Jean-Philippe Attané
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, Grenoble, France
| | - Manuel Bibes
- Unité Mixte de Physique CNRS/Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France.
| |
Collapse
|
11
|
Singh G, Jouan A, Herranz G, Scigaj M, Sánchez F, Benfatto L, Caprara S, Grilli M, Saiz G, Couëdo F, Feuillet-Palma C, Lesueur J, Bergeal N. Gap suppression at a Lifshitz transition in a multi-condensate superconductor. Nat Mater 2019; 18:948-954. [PMID: 31086324 DOI: 10.1038/s41563-019-0354-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
In multi-orbital materials, superconductivity can exhibit several coupled condensates. In this context, quantum confinement in two-dimensional superconducting oxide interfaces offers new degrees of freedom to engineer the band structure and selectively control the occupancy of 3d orbitals by electrostatic doping. Here, we use resonant microwave transport to extract the superfluid stiffness of the (110)-oriented LaAlO3/SrTiO3 interface in the entire phase diagram. We provide evidence of a transition from single-condensate to two-condensate superconductivity driven by continuous and reversible electrostatic doping, which we relate to the Lifshitz transition between 3d bands based on numerical simulations of the quantum well. We find that the superconducting gap is suppressed while the second band is populated, challenging Bardeen-Cooper-Schrieffer theory. We ascribe this behaviour to the existence of superconducting order parameters with opposite signs in the two condensates due to repulsive coupling. Our findings offer an innovative perspective on the possibility to tune and control multiple-orbital physics in superconducting interfaces.
Collapse
Affiliation(s)
- G Singh
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - A Jouan
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - G Herranz
- Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, Bellaterra, Catalonia, Spain
| | - M Scigaj
- Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, Bellaterra, Catalonia, Spain
| | - F Sánchez
- Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, Bellaterra, Catalonia, Spain
| | - L Benfatto
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Roma, Italy
- Dipartimento di Fisica Università di Roma 'La Sapienza', Roma, Italy
| | - S Caprara
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Roma, Italy
- Dipartimento di Fisica Università di Roma 'La Sapienza', Roma, Italy
| | - M Grilli
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Roma, Italy
- Dipartimento di Fisica Università di Roma 'La Sapienza', Roma, Italy
| | - G Saiz
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - F Couëdo
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, Paris, France.
- Université Pierre and Marie Curie, Sorbonne-Université, Paris, France.
| |
Collapse
|
12
|
Singh G, Jouan A, Benfatto L, Couëdo F, Kumar P, Dogra A, Budhani RC, Caprara S, Grilli M, Lesne E, Barthélémy A, Bibes M, Feuillet-Palma C, Lesueur J, Bergeal N. Competition between electron pairing and phase coherence in superconducting interfaces. Nat Commun 2018; 9:407. [PMID: 29379023 PMCID: PMC5789063 DOI: 10.1038/s41467-018-02907-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 01/08/2018] [Indexed: 11/29/2022] Open
Abstract
In LaAlO3/SrTiO3 heterostructures, a gate tunable superconducting electron gas is confined in a quantum well at the interface between two insulating oxides. Remarkably, the gas coexists with both magnetism and strong Rashba spin-orbit coupling. However, both the origin of superconductivity and the nature of the transition to the normal state over the whole doping range remain elusive. Here we use resonant microwave transport to extract the superfluid stiffness and the superconducting gap energy of the LaAlO3/SrTiO3 interface as a function of carrier density. We show that the superconducting phase diagram of this system is controlled by the competition between electron pairing and phase coherence. The analysis of the superfluid density reveals that only a very small fraction of the electrons condenses into the superconducting state. We propose that this corresponds to the weak filling of high-energy dxz/dyz bands in the quantum well, more apt to host superconductivity.
Collapse
Affiliation(s)
- G Singh
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France
| | - A Jouan
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France
| | - L Benfatto
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Piazzale A. Moro 5, 00185, Roma, Italy.
- Dipartimento di Fisica Università di Roma "La Sapienza", Piazzale A. Moro 5, 00185, Roma, Italy.
| | - F Couëdo
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France
| | - P Kumar
- National Physical Laboratory, Council of Scientific and Industrial Research (CSIR), Dr. K.S. Krishnan Marg, New Delhi, 110012, India
| | - A Dogra
- National Physical Laboratory, Council of Scientific and Industrial Research (CSIR), Dr. K.S. Krishnan Marg, New Delhi, 110012, India
| | - R C Budhani
- Condensed Matter Low Dimensional Systems Laboratory, Department of Physics, Indian Institute of Technology, Kanpur, 208016, India
| | - S Caprara
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Piazzale A. Moro 5, 00185, Roma, Italy
- Dipartimento di Fisica Università di Roma "La Sapienza", Piazzale A. Moro 5, 00185, Roma, Italy
| | - M Grilli
- Institute for Complex Systems (ISC-CNR), UOS Sapienza, Piazzale A. Moro 5, 00185, Roma, Italy
- Dipartimento di Fisica Università di Roma "La Sapienza", Piazzale A. Moro 5, 00185, Roma, Italy
| | - E Lesne
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767, Palaiseau, France
| | - A Barthélémy
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767, Palaiseau, France
| | - M Bibes
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767, Palaiseau, France
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris, PSL Research University, CNRS, 10 Rue Vauquelin, 75005, Paris, France.
- Université Pierre and Marie Curie, Sorbonne-Universités, 75005, Paris, France.
| |
Collapse
|
13
|
Scopigno N, Bucheli D, Caprara S, Biscaras J, Bergeal N, Lesueur J, Grilli M. Phase Separation from Electron Confinement at Oxide Interfaces. Phys Rev Lett 2016; 116:026804. [PMID: 26824560 DOI: 10.1103/physrevlett.116.026804] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 06/05/2023]
Abstract
Oxide heterostructures are of great interest for both fundamental and applicative reasons. In particular, the two-dimensional electron gas at the LaAlO_{3}/SrTiO_{3} or LaTiO_{3}/SrTiO_{3} interfaces displays many different properties and functionalities. However, there are clear experimental indications that the interface electronic state is strongly inhomogeneous and therefore it is crucial to investigate possible intrinsic mechanisms underlying this inhomogeneity. Here, the electrostatic potential confining the electron gas at the interface is calculated self-consistently, finding that such confinement may induce phase separation, to avoid a thermodynamically unstable state with a negative compressibility. This provides a robust mechanism for the inhomogeneous character of these interfaces.
Collapse
Affiliation(s)
- N Scopigno
- Dipartimento di Fisica, Università di Roma "Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - D Bucheli
- Dipartimento di Fisica, Università di Roma "Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - S Caprara
- Dipartimento di Fisica, Università di Roma "Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy
- ISC-CNR and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Roma "Sapienza"
| | - J Biscaras
- Laboratoire de Physique et d'Étude des Matériaux, CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Étude des Matériaux, CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - J Lesueur
- Laboratoire de Physique et d'Étude des Matériaux, CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - M Grilli
- Dipartimento di Fisica, Università di Roma "Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy
- ISC-CNR and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Roma "Sapienza"
| |
Collapse
|
14
|
Caprara S, Bergeal N, Lesueur J, Grilli M. Interplay between density and superconducting quantum critical fluctuations. J Phys Condens Matter 2015; 27:425701. [PMID: 26416761 DOI: 10.1088/0953-8984/27/42/425701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We consider the case of a density-driven metal-superconductor transition in the proximity of an electronic phase separation. In particular, we investigate the interplay between superconducting fluctuations and density fluctuations, which become quantum critical when the electronic phase separation vanishes at zero temperature into a quantum critical point. In this situation, the critical dynamical density fluctuations strongly affect the dynamics of the Cooper-pair fluctuations, which acquire a more singular character with a z = 3 dynamical critical index. This gives rise to a scenario that possibly rules the disappearance of superconductivity when the electron density is reduced by electrostatic gating at the LaAlO3/SrTiO3 interface.
Collapse
Affiliation(s)
- S Caprara
- Dipartimento di Fisica, Università di Roma Sapienza, Piazzale Aldo Moro 5, I-00185 Roma, Italy. Istituto dei Sistemi Complessi CNR and CNISM Unità di Roma Sapienza, 00185 Roma, Italy
| | | | | | | |
Collapse
|
15
|
Hurand S, Jouan A, Feuillet-Palma C, Singh G, Biscaras J, Lesne E, Reyren N, Barthélémy A, Bibes M, Villegas JE, Ulysse C, Lafosse X, Pannetier-Lecoeur M, Caprara S, Grilli M, Lesueur J, Bergeal N. Field-effect control of superconductivity and Rashba spin-orbit coupling in top-gated LaAlO3/SrTiO3 devices. Sci Rep 2015; 5:12751. [PMID: 26244916 PMCID: PMC4525493 DOI: 10.1038/srep12751] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 07/06/2015] [Indexed: 11/18/2022] Open
Abstract
The recent development in the fabrication of artificial oxide heterostructures opens new avenues in the field of quantum materials by enabling the manipulation of the charge, spin and orbital degrees of freedom. In this context, the discovery of two-dimensional electron gases (2-DEGs) at LaAlO3/SrTiO3 interfaces, which exhibit both superconductivity and strong Rashba spin-orbit coupling (SOC), represents a major breakthrough. Here, we report on the realisation of a field-effect LaAlO3/SrTiO3 device, whose physical properties, including superconductivity and SOC, can be tuned over a wide range by a top-gate voltage. We derive a phase diagram, which emphasises a field-effect-induced superconductor-to-insulator quantum phase transition. Magneto-transport measurements show that the Rashba coupling constant increases linearly with the interfacial electric field. Our results pave the way for the realisation of mesoscopic devices, where these two properties can be manipulated on a local scale by means of top-gates.
Collapse
Affiliation(s)
- S Hurand
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - A Jouan
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - C Feuillet-Palma
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - G Singh
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - J Biscaras
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - E Lesne
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - N Reyren
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - A Barthélémy
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - M Bibes
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - J E Villegas
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - C Ulysse
- Laboratoire de Photonique et de Nanostructures LPN-CNRS, Route de Nozay, 91460 Marcoussis, France
| | - X Lafosse
- Laboratoire de Photonique et de Nanostructures LPN-CNRS, Route de Nozay, 91460 Marcoussis, France
| | - M Pannetier-Lecoeur
- DSM/IRAMIS/SPEC - CNRS UMR 3680, CEA Saclay, F-91191 Gif sur Yvette Cedex, France
| | - S Caprara
- Dipartimento di Fisica Università di Roma "La Sapienza", piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - M Grilli
- Dipartimento di Fisica Università di Roma "La Sapienza", piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - J Lesueur
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| | - N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux -CNRS-ESPCI ParisTech-UPMC, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France
| |
Collapse
|
16
|
Herranz G, Singh G, Bergeal N, Jouan A, Lesueur J, Gázquez J, Varela M, Scigaj M, Dix N, Sánchez F, Fontcuberta J. Engineering two-dimensional superconductivity and Rashba spin-orbit coupling in LaAlO₃/SrTiO₃ quantum wells by selective orbital occupancy. Nat Commun 2015; 6:6028. [PMID: 25583368 PMCID: PMC4308716 DOI: 10.1038/ncomms7028] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/03/2014] [Indexed: 11/09/2022] Open
Abstract
The discovery of two-dimensional electron gases (2DEGs) at oxide interfaces-involving electrons in narrow d-bands-has broken new ground, enabling the access to correlated states that are unreachable in conventional semiconductors based on s- and p- electrons. There is a growing consensus that emerging properties at these novel quantum wells-such as 2D superconductivity and magnetism-are intimately connected to specific orbital symmetries in the 2DEG sub-band structure. Here we show that crystal orientation allows selective orbital occupancy, disclosing unprecedented ways to tailor the 2DEG properties. By carrying out electrostatic gating experiments in LaAlO3/SrTiO3 wells of different crystal orientations, we show that the spatial extension and anisotropy of the 2D superconductivity and the Rashba spin-orbit field can be largely modulated by controlling the 2DEG sub-band filling. Such an orientational tuning expands the possibilities for electronic engineering of 2DEGs at LaAlO3/SrTiO3 interfaces.
Collapse
Affiliation(s)
- Gervasi Herranz
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain
| | - Gyanendra Singh
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, PSL University, 10 rue Vauquelin, 75005 Paris, France
| | - Nicolas Bergeal
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, PSL University, 10 rue Vauquelin, 75005 Paris, France
| | - Alexis Jouan
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, PSL University, 10 rue Vauquelin, 75005 Paris, France
| | - Jérôme Lesueur
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, PSL University, 10 rue Vauquelin, 75005 Paris, France
| | - Jaume Gázquez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain
| | - María Varela
- 1] Materials Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA [2] GFMC, Department de Fisica Aplicada III &Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Mateusz Scigaj
- 1] Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain [2] Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Catalonia, Spain
| | - Nico Dix
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain
| | - Florencio Sánchez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain
| | - Josep Fontcuberta
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain
| |
Collapse
|
17
|
Biscaras J, Hurand S, Feuillet-Palma C, Rastogi A, Budhani RC, Reyren N, Lesne E, Lesueur J, Bergeal N. Limit of the electrostatic doping in two-dimensional electron gases of LaXO₃(X = Al, Ti)/SrTiO₃. Sci Rep 2014; 4:6788. [PMID: 25346028 PMCID: PMC4209450 DOI: 10.1038/srep06788] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 10/06/2014] [Indexed: 11/15/2022] Open
Abstract
In LaTiO3/SrTiO3 and LaAlO3/SrTiO3 heterostructures, the bending of the SrTiO3 conduction band at the interface forms a quantum well that contains a superconducting two-dimensional electron gas (2-DEG). Its carrier density and electronic properties, such as superconductivity and Rashba spin-orbit coupling can be controlled by electrostatic gating. In this article we show that the Fermi energy lies intrinsically near the top of the quantum well. Beyond a filling threshold, electrons added by electrostatic gating escape from the well, hence limiting the possibility to reach a highly-doped regime. This leads to an irreversible doping regime where all the electronic properties of the 2-DEG, such as its resistivity and its superconducting transition temperature, saturate. The escape mechanism can be described by the simple analytical model we propose.
Collapse
Affiliation(s)
- J Biscaras
- LPEM- UMR8213/CNRS - ESPCI ParisTech - UPMC, 10 rue Vauquelin - 75005 Paris, France
| | - S Hurand
- LPEM- UMR8213/CNRS - ESPCI ParisTech - UPMC, 10 rue Vauquelin - 75005 Paris, France
| | - C Feuillet-Palma
- LPEM- UMR8213/CNRS - ESPCI ParisTech - UPMC, 10 rue Vauquelin - 75005 Paris, France
| | - A Rastogi
- Condensed Matter - Low Dimensional Systems Laboratory, Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - R C Budhani
- 1] Condensed Matter - Low Dimensional Systems Laboratory, Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India [2] National Physical Laboratory, New Delhi - 110012, India and
| | - N Reyren
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - E Lesne
- Unité Mixte de Physique CNRS-Thales, 1 Av. A. Fresnel, 91767 Palaiseau, France
| | - J Lesueur
- LPEM- UMR8213/CNRS - ESPCI ParisTech - UPMC, 10 rue Vauquelin - 75005 Paris, France
| | - N Bergeal
- LPEM- UMR8213/CNRS - ESPCI ParisTech - UPMC, 10 rue Vauquelin - 75005 Paris, France
| |
Collapse
|
18
|
Trastoy J, Malnou M, Ulysse C, Bernard R, Bergeal N, Faini G, Lesueur J, Briatico J, Villegas JE. Freezing and thawing of artificial ice by thermal switching of geometric frustration in magnetic flux lattices. Nat Nanotechnol 2014; 9:710-715. [PMID: 25129072 DOI: 10.1038/nnano.2014.158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 07/02/2014] [Indexed: 06/03/2023]
Abstract
The problem of an ensemble of repulsive particles on a potential-energy landscape is common to many physical systems and has been studied in multiple artificial playgrounds. However, the latter usually involve fixed energy landscapes, thereby impeding in situ investigations of the particles' collective response to controlled changes in the landscape geometry. Here, we experimentally realize a system in which the geometry of the potential-energy landscape can be switched using temperature as the control knob. This realization is based on a high-temperature superconductor in which we engineer a nanoscale spatial modulation of the superconducting condensate. Depending on the temperature, the flux quanta induced by an applied magnetic field see either a geometrically frustrated energy landscape that favours an ice-like flux ordering, or an unfrustrated landscape that yields a periodic flux distribution. This effect is reflected in a dramatic change in the superconductor's magneto-transport. The thermal switching of the energy landscape geometry opens new opportunities for the study of ordering and reorganization in repulsive particle manifolds.
Collapse
Affiliation(s)
- J Trastoy
- 1] Unité Mixte de Physique CNRS/Thales, 1 ave. A. Fresnel, 91767 Palaiseau, France [2] Université Paris Sud, 91405 Orsay, France
| | - M Malnou
- LPEM, ESPCI-CNRS-UPMC, 10 rue Vauquelin 75231 Paris, France
| | - C Ulysse
- CNRS, Phynano Team, Laboratoire de Photonique et de Nanostructures, route de Nozay, 91460 Marcoussis, France
| | - R Bernard
- 1] Unité Mixte de Physique CNRS/Thales, 1 ave. A. Fresnel, 91767 Palaiseau, France [2] Université Paris Sud, 91405 Orsay, France
| | - N Bergeal
- LPEM, ESPCI-CNRS-UPMC, 10 rue Vauquelin 75231 Paris, France
| | - G Faini
- CNRS, Phynano Team, Laboratoire de Photonique et de Nanostructures, route de Nozay, 91460 Marcoussis, France
| | - J Lesueur
- LPEM, ESPCI-CNRS-UPMC, 10 rue Vauquelin 75231 Paris, France
| | - J Briatico
- 1] Unité Mixte de Physique CNRS/Thales, 1 ave. A. Fresnel, 91767 Palaiseau, France [2] Université Paris Sud, 91405 Orsay, France
| | - Javier E Villegas
- 1] Unité Mixte de Physique CNRS/Thales, 1 ave. A. Fresnel, 91767 Palaiseau, France [2] Université Paris Sud, 91405 Orsay, France
| |
Collapse
|
19
|
Biscaras J, Bergeal N, Hurand S, Feuillet-Palma C, Rastogi A, Budhani RC, Grilli M, Caprara S, Lesueur J. Multiple quantum criticality in a two-dimensional superconductor. Nat Mater 2013; 12:542-548. [PMID: 23584144 DOI: 10.1038/nmat3624] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 03/06/2013] [Indexed: 06/02/2023]
Abstract
The diverse phenomena associated with the two-dimensional electron gas (2DEG) that occurs at oxide interfaces include, among others, exceptional carrier mobilities, magnetism and superconductivity. Although these have mostly been the focus of interest for potential future applications, they also offer an opportunity for studying more fundamental quantum many-body effects. Here, we examine the magnetic-field-driven quantum phase transition that occurs in electrostatically gated superconducting LaTiO3/SrTiO3 interfaces. Through a finite-size scaling analysis, we show that it belongs to the (2+1)D XY model universality class. The system can be described as a disordered array of superconducting puddles coupled by a 2DEG and, depending on its conductance, the observed critical behaviour is single (corresponding to the long-range phase coherence in the whole array) or double (one related to local phase coherence, the other one to the array). A phase diagram illustrating the dependence of the critical field on the 2DEG conductance is constructed, and shown to agree with theoretical proposals. Moreover, by retrieving the coherence-length critical exponent ν, we show that the quantum critical behaviour can be clean or dirty according to the Harris criterion, depending on whether the phase-coherence length is smaller or larger than the size of the puddles.
Collapse
Affiliation(s)
- J Biscaras
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, 10 rue Vauquelin, 75005 Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abdo B, Sliwa K, Schackert F, Bergeal N, Hatridge M, Frunzio L, Stone AD, Devoret M. Full coherent frequency conversion between two propagating microwave modes. Phys Rev Lett 2013; 110:173902. [PMID: 23679729 DOI: 10.1103/physrevlett.110.173902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Indexed: 06/02/2023]
Abstract
We demonstrate full frequency conversion in the microwave domain using a Josephson three-wave mixing device pumped at the difference between the frequencies of its fundamental eigenmodes. By measuring the signal output as a function of the intensity and phase of the three input signal, idler, and pump tones, we show that the device functions as a controllable three-wave beam splitter or combiner for propagating microwave modes at the single-photon level, in accordance with theory. Losses at the full conversion point are found to be less than 10(-2). Potential applications of the device include quantum information transduction and realization of an ultrasensitive interferometer with controllable feedback.
Collapse
Affiliation(s)
- Baleegh Abdo
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Félix LA, Sirena M, Guzmán LAA, Sutter JG, Vargas SP, Steren LB, Bernard R, Trastoy J, Villegas JE, Briático J, Bergeal N, Lesueur J, Faini G. Structural and electrical characterization of ultra-thin SrTiO3 tunnel barriers grown over YBa2Cu3O7 electrodes for the development of high Tc Josephson junctions. Nanotechnology 2012; 23:495715. [PMID: 23154521 DOI: 10.1088/0957-4484/23/49/495715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The transport properties of ultra-thin SrTiO(3) (STO) layers grown over YBa(2)Cu(3)O(7) electrodes were studied by conductive atomic force microscopy at the nano-scale. A very good control of the barrier thickness was achieved during the deposition process. A phenomenological approach was used to obtain critical parameters regarding the structural and electrical properties of the system. The STO layers present an energy barrier of 0.9 eV and an attenuation length of 0.23 nm, indicating very good insulating properties for the development of high-quality Josephson junctions.
Collapse
Affiliation(s)
- L Avilés Félix
- Centro Atómico Bariloche, Instituto Balseiro-CNEA, Universidad Nacional de Cuyo, Bariloche, Rio Negro, Argentina.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Biscaras J, Bergeal N, Hurand S, Grossetête C, Rastogi A, Budhani RC, LeBoeuf D, Proust C, Lesueur J. Two-dimensional superconducting phase in LaTiO3/SrTiO3 heterostructures induced by high-mobility carrier doping. Phys Rev Lett 2012; 108:247004. [PMID: 23004312 DOI: 10.1103/physrevlett.108.247004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Indexed: 06/01/2023]
Abstract
In this Letter, we show that a superconducting two-dimensional electron gas is formed at the LaTiO3/SrTiO3 interface whose transition temperature can be modulated by a back-gate voltage. The gas consists of two types of carriers: a majority of low-mobility carriers always present, and a few high-mobility ones that can be injected by electrostatic doping. The calculation of the electron spatial distribution in the confinement potential shows that the high-mobility electrons responsible for superconductivity set at the edge of the gas whose extension can be tuned by the field effect.
Collapse
Affiliation(s)
- J Biscaras
- LPEM-UMR8213/CNRS-ESPCI ParisTech-UPMC, 10 rue Vauquelin-75005 Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Bergeal N, Schackert F, Frunzio L, Devoret MH. Two-mode correlation of microwave quantum noise generated by parametric down-conversion. Phys Rev Lett 2012; 108:123902. [PMID: 22540583 DOI: 10.1103/physrevlett.108.123902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Indexed: 05/31/2023]
Abstract
In this Letter, we report the observation of the correlation between two modes of microwave radiation resulting from the amplification of quantum noise by the Josephson parametric converter. This process, seen from the pump, can be viewed as parametric down-conversion. The correlation is measured by an interference experiment displaying a contrast better than 99% with a number of photons per mode greater than 250,000. Dispersive measurements of mesoscopic systems and quantum encryption can benefit from this development.
Collapse
Affiliation(s)
- N Bergeal
- Laboratoire de Physique et d'Etude des Matériaux-UMR8213-CNRS, ESPCI ParisTech, 10 Rue Vauquelin-75005 Paris, France
| | | | | | | |
Collapse
|
24
|
Villegas JE, Swiecicki I, Bernard R, Crassous A, Briatico J, Wolf T, Bergeal N, Lesueur J, Ulysse C, Faini G, Hallet X, Piraux L. Imprinting nanoporous alumina patterns into the magneto-transport of oxide superconductors. Nanotechnology 2011; 22:075302. [PMID: 21233542 DOI: 10.1088/0957-4484/22/7/075302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We used oxygen ion irradiation to transfer the nanoscale pattern of a porous alumina mask into high-T(C) superconducting thin films. This causes a nanoscale spatial modulation of superconductivity and strongly affects the magneto-transport below T(C), which shows a series of periodic oscillations reminiscent of the Little-Parks effect in superconducting wire networks. This irradiation technique could be extended to other oxide materials in order to induce ordered nanoscale phase segregation.
Collapse
Affiliation(s)
- J E Villegas
- Unité Mixte de Physique CNRS/Thales, Palaiseau, France.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Biscaras J, Bergeal N, Kushwaha A, Wolf T, Rastogi A, Budhani R, Lesueur J. Two-dimensional superconductivity at a Mott insulator/band insulator interface LaTiO3/SrTiO3. Nat Commun 2010; 1:89. [DOI: 10.1038/ncomms1084] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 09/06/2010] [Indexed: 11/09/2022] Open
|
26
|
Bergeal N, Dubost V, Noat Y, Sacks W, Roditchev D, Emery N, Hérold C, Marêché JF, Lagrange P, Loupias G. Scanning tunneling spectroscopy on the novel superconductor CaC6. Phys Rev Lett 2006; 97:077003. [PMID: 17026267 DOI: 10.1103/physrevlett.97.077003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Indexed: 05/12/2023]
Abstract
We present scanning tunneling microscopy and spectroscopy of the newly discovered superconductor CaC6. The tunneling conductance spectra, measured between 3 and 15 K, show a clear superconducting gap in the quasiparticle density of states. The gap function extracted from the spectra is in good agreement with the conventional BCS theory with Delta0=1.6+/-0.2 meV. The possibility of gap anisotropy and two-gap superconductivity is also discussed. In a magnetic field, direct imaging of the vortices allows us to deduce a coherence length in the ab plane xiab approximately 33 nm.
Collapse
Affiliation(s)
- N Bergeal
- Institut des Nanosciences de Paris, Universités Paris 6 et 7, UMR 7588 au CNRS, 140 rue de Lourmel, 75015 Paris, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|