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Chandra P, Lonzarich GG, Rowley SE, Scott JF. Prospects and applications near ferroelectric quantum phase transitions: a key issues review. Rep Prog Phys 2017; 80:112502. [PMID: 28752823 DOI: 10.1088/1361-6633/aa82d2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The emergence of complex and fascinating states of quantum matter in the neighborhood of zero temperature phase transitions suggests that such quantum phenomena should be studied in a variety of settings. Advanced technologies of the future may be fabricated from materials where the cooperative behavior of charge, spin and current can be manipulated at cryogenic temperatures. The progagating lattice dynamics of displacive ferroelectrics make them appealing for the study of quantum critical phenomena that is characterized by both space- and time-dependent quantities. In this key issues article we aim to provide a self-contained overview of ferroelectrics near quantum phase transitions. Unlike most magnetic cases, the ferroelectric quantum critical point can be tuned experimentally to reside at, above or below its upper critical dimension; this feature allows for detailed interplay between experiment and theory using both scaling and self-consistent field models. Empirically the sensitivity of the ferroelectric T c's to external and to chemical pressure gives practical access to a broad range of temperature behavior over several hundreds of Kelvin. Additional degrees of freedom like charge and spin can be added and characterized systematically. Satellite memories, electrocaloric cooling and low-loss phased-array radar are among possible applications of low-temperature ferroelectrics. We end with open questions for future research that include textured polarization states and unusual forms of superconductivity that remain to be understood theoretically.
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Affiliation(s)
- P Chandra
- Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, United States of America
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Rowley SE, Hadjimichael M, Ali MN, Durmaz YC, Lashley JC, Cava RJ, Scott JF. Quantum criticality in a uniaxial organic ferroelectric. J Phys Condens Matter 2015; 27:395901. [PMID: 26360383 DOI: 10.1088/0953-8984/27/39/395901] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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
Tris-sarcosine calcium chloride (TSCC) is a highly uniaxial ferroelectric with a Curie temperature of approximately 130 K. By suppressing ferroelectricity with bromine substitution on the chlorine sites, pure single crystals were tuned through a ferroelectric quantum phase transition. The resulting quantum critical regime was investigated in detail and was found to persist up to temperatures of at least 30-40 K. The nature of long-range dipole interactions in uniaxial materials, which lead to non-analytical terms in the free-energy expansion in the polarization, predict a dielectric susceptibility varying as 1/T(3)close to the quantum critical point. Rather than this, we find that the dielectric susceptibility varies as 1/T(2) as expected and observed in better known multi-axial systems. We explain this result by identifying the ultra-weak nature of the dipole moments in the TSCC family of crystals. Interestingly, we observe a shallow minimum in the inverse dielectric function at low temperatures close to the quantum critical point in paraelectric samples that may be attributed to the coupling of quantum polarization and strain fields. Finally, we present results of the heat capacity and electro-caloric effect and explain how the time dependence of the polarization in ferroelectrics and paraelectrics should be considered when making quantitative estimates of temperature changes induced by applied electric fields.
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Affiliation(s)
- S E Rowley
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK. CBPF, Rua Dr Xavier Sigaud 150, Urca, Rio de Janeiro, 22290-180, Brazil
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Scott JF, Schilling A, Rowley SE, Gregg JM. Some current problems in perovskite nano-ferroelectrics and multiferroics: kinetically-limited systems of finite lateral size. Sci Technol Adv Mater 2015; 16:036001. [PMID: 27877812 PMCID: PMC5099849 DOI: 10.1088/1468-6996/16/3/036001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 03/12/2015] [Accepted: 03/16/2015] [Indexed: 06/06/2023]
Abstract
We describe some unsolved problems of current interest; these involve quantum critical points in ferroelectrics and problems which are not amenable to the usual density functional theory, nor to classical Landau free energy approaches (they are kinetically limited), nor even to the Landau-Kittel relationship for domain size (they do not satisfy the assumption of infinite lateral diameter) because they are dominated by finite aperiodic boundary conditions.
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Affiliation(s)
- James F Scott
- Cavendish Laboratory, Dept. Physics, Cambridge University, Cambridge, UK
- Depts. of Chemistry and Physics, St. Andrews University, St. Andrews, UK
| | | | - S E Rowley
- Cavendish Laboratory, Dept. Physics, Cambridge University, Cambridge, UK
- CBPF, Rua Dr Xavier Sigaud 150, Urca, Rio de Janeiro, RJ 22290-180, Brazil
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Luo Y, Pourovskii L, Rowley SE, Li Y, Feng C, Georges A, Dai J, Cao G, Xu Z, Si Q, Ong NP. Heavy-fermion quantum criticality and destruction of the Kondo effect in a nickel oxypnictide. Nat Mater 2014; 13:777-781. [PMID: 24859644 DOI: 10.1038/nmat3991] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 04/24/2014] [Indexed: 06/03/2023]
Abstract
A quantum critical point arises at a continuous transformation between distinct phases of matter at zero temperature. Studies in antiferromagnetic heavy-fermion materials have revealed that quantum criticality has several classes, with an unconventional type that involves a critical destruction of the Kondo entanglement. To understand such varieties, it is important to extend the materials basis beyond the usual setting of intermetallic compounds. Here we show that a nickel oxypnictide, CeNiAsO, exhibits a heavy-fermion antiferromagnetic quantum critical point as a function of either pressure or P/As substitution. At the quantum critical point, non-Fermi-liquid behaviour appears, which is accompanied by a divergent effective carrier mass. Across the quantum critical point, the low-temperature Hall coefficient undergoes a rapid sign change, suggesting a sudden jump of the Fermi surface and a destruction of the Kondo effect. Our results imply that the enormous materials basis for the oxypnictides, which has been so crucial in the search for high-temperature superconductivity, will also play a vital role in the effort to establish the universality classes of quantum criticality in strongly correlated electron systems.
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Affiliation(s)
- Yongkang Luo
- 1] Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China [2] Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Leonid Pourovskii
- 1] Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France [2] Swedish e-science Research Centre (SeRC), Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 58183, Sweden
| | - S E Rowley
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Yuke Li
- Department of Physics, Hangzhou Normal University, Hangzhou 310036, China
| | - Chunmu Feng
- Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China
| | - Antoine Georges
- Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - Jianhui Dai
- Department of Physics, Hangzhou Normal University, Hangzhou 310036, China
| | - Guanghan Cao
- Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China
| | - Zhu'an Xu
- Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China
| | - Qimiao Si
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - N P Ong
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
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Lashley JC, Munns JHD, Echizen M, Ali MN, Rowley SE, Scott JF. Phase transitions in the brominated ferroelectric tris-sarcosine calcium chloride. Adv Mater 2014; 26:3860-3866. [PMID: 24789107 DOI: 10.1002/adma.201305065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/24/2014] [Indexed: 06/03/2023]
Affiliation(s)
- J C Lashley
- Los Alamos National Laboratory, Los Alamos, New Mexico 1663, 87545, USA; Cavendish Laboratory, Cambridge University, J. J. Thomson Avenue, Cambridge, CB3 0HE, England
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Sackville Hamilton AC, Lampronti GI, Rowley SE, Dutton SE. Enhancement of the magnetocaloric effect driven by changes in the crystal structure of Al-doped GGG, Gd3Ga5-xAlxO12 (0 ≤x ≤5). J Phys Condens Matter 2014; 26:116001. [PMID: 24590065 DOI: 10.1088/0953-8984/26/11/116001] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The Gd3Ga5-xAlxO12 (0 ≤ x ≤ 5) solid solution has been prepared using ceramic synthesis routes and the structural and magnetic properties were investigated using x-ray diffraction, magnetic susceptibility, χ, and isothermal magnetisation, M(H), measurements. Our results indicate a contraction of the unit cell and more significant antiferromagnetic interactions as x increases. Despite the decrease in the magnetic polarisation on the application of a field and the corresponding decrease in the change in the magnetic entropy, ΔS, we find that Gd3Al5O12 has a significantly higher observed (17%) and theoretical (14%) ΔS per unit mass than Gd3Ga5O12. The theoretical increase in ΔS per unit volume (7%) is offset by the increased antiferromagnetic interactions in Gd3Al5O12. The differences in ΔS are driven by a decrease in both the mass and the density as Al ions replace Ga ions. These results highlight the importance of changes to the crystal structure when considering materials for solid state magnetic cooling.
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Affiliation(s)
- A C Sackville Hamilton
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
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