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Liu JY, Hu J, Graf D, Zou T, Zhu M, Shi Y, Che S, Radmanesh SMA, Lau CN, Spinu L, Cao HB, Ke X, Mao ZQ. Unusual interlayer quantum transport behavior caused by the zeroth Landau level in YbMnBi 2. Nat Commun 2017; 8:646. [PMID: 28935862 PMCID: PMC5608808 DOI: 10.1038/s41467-017-00673-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [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: 08/25/2016] [Accepted: 07/18/2017] [Indexed: 11/23/2022] Open
Abstract
Relativistic fermions in topological quantum materials are characterized by linear energy-momentum dispersion near band crossing points. Under magnetic fields, relativistic fermions acquire Berry phase of π in cyclotron motion, leading to a zeroth Landau level (LL) at the crossing point, a signature unique to relativistic fermions. Here we report the unusual interlayer quantum transport behavior resulting from the zeroth LL mode observed in the time reversal symmetry breaking type II Weyl semimetal YbMnBi2. The interlayer magnetoresistivity and Hall conductivity of this material are found to exhibit surprising angular dependences under high fields, which can be well fitted by a model, which considers the interlayer quantum tunneling transport of the zeroth LL's Weyl fermions. Our results shed light on the unusual role of zeroth LLl mode in transport.The transport behavior of the carriers residing in the lowest Landau level is hard to observe in most topological materials. Here, Liu et al. report a surprising angular dependence of the interlayer magnetoresistivity and Hall conductivity arising from the lowest Landau level under high magnetic field in type II Weyl semimetal YbMnBi2.
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Affiliation(s)
- J Y Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA
| | - J Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.
| | - D Graf
- National High Magnetic Field Lab, Tallahassee, FL, 32310, USA
| | - T Zou
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - M Zhu
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Y Shi
- Department of Physics, University of California, Riverside, CA, 92521, USA
| | - S Che
- Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH, 43210, USA
| | - S M A Radmanesh
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, 70148, USA
| | - C N Lau
- Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH, 43210, USA
| | - L Spinu
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, 70148, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - X Ke
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.
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Liu JY, Hu J, Zhang Q, Graf D, Cao HB, Radmanesh SMA, Adams DJ, Zhu YL, Cheng GF, Liu X, Phelan WA, Wei J, Jaime M, Balakirev F, Tennant DA, DiTusa JF, Chiorescu I, Spinu L, Mao ZQ. A magnetic topological semimetal Sr 1-yMn 1-zSb 2 (y, z < 0.1). Nat Mater 2017; 16:905-910. [PMID: 28740190 DOI: 10.1038/nmat4953] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
Weyl (WSMs) evolve from Dirac semimetals in the presence of broken time-reversal symmetry (TRS) or space-inversion symmetry. The WSM phases in TaAs-class materials and photonic crystals are due to the loss of space-inversion symmetry. For TRS-breaking WSMs, despite numerous theoretical and experimental efforts, few examples have been reported. In this Article, we report a new type of magnetic semimetal Sr1-yMn1-zSb2 (y, z < 0.1) with nearly massless relativistic fermion behaviour (m∗ = 0.04 - 0.05m0, where m0 is the free-electron mass). This material exhibits a ferromagnetic order for 304 K < T < 565 K, but a canted antiferromagnetic order with a ferromagnetic component for T < 304 K. The combination of relativistic fermion behaviour and ferromagnetism in Sr1-yMn1-zSb2 offers a rare opportunity to investigate the interplay between relativistic fermions and spontaneous TRS breaking.
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Affiliation(s)
- J Y Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - J Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - Q Zhang
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D Graf
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - H B Cao
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S M A Radmanesh
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - D J Adams
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Y L Zhu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - G F Cheng
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - X Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - W A Phelan
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - J Wei
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - M Jaime
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Balakirev
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D A Tennant
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J F DiTusa
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - I Chiorescu
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - L Spinu
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
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Liu J, Hu J, Cao H, Zhu Y, Chuang A, Graf D, Adams DJ, Radmanesh SMA, Spinu L, Chiorescu I, Mao Z. Nearly massless Dirac fermions hosted by Sb square net in BaMnSb2. Sci Rep 2016; 6:30525. [PMID: 27466151 PMCID: PMC4964361 DOI: 10.1038/srep30525] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [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: 05/18/2016] [Accepted: 07/04/2016] [Indexed: 11/09/2022] Open
Abstract
Layered compounds AMnBi2 (A = Ca, Sr, Ba, or rare earth element) have been established as Dirac materials. Dirac electrons generated by the two-dimensional (2D) Bi square net in these materials are normally massive due to the presence of a spin-orbital coupling (SOC) induced gap at Dirac nodes. Here we report that the Sb square net in an isostructural compound BaMnSb2 can host nearly massless Dirac fermions. We observed strong Shubnikov-de Haas (SdH) oscillations in this material. From the analyses of the SdH oscillations, we find key signatures of Dirac fermions, including light effective mass (~0.052m0; m0, mass of free electron), high quantum mobility (1280 cm(2)V(-1)S(-1)) and a π Berry phase accumulated along cyclotron orbit. Compared with AMnBi2, BaMnSb2 also exhibits much more significant quasi two-dimensional (2D) electronic structure, with the out-of-plane transport showing nonmetallic conduction below 120 K and the ratio of the out-of-plane and in-plane resistivity reaching ~670. Additionally, BaMnSb2 also exhibits a G-type antiferromagnetic order below 283 K. The combination of nearly massless Dirac fermions on quasi-2D planes with a magnetic order makes BaMnSb2 an intriguing platform for seeking novel exotic phenomena of massless Dirac electrons.
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Affiliation(s)
- Jinyu Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70018, USA
| | - Jin Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70018, USA
| | - Huibo Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, TN 37830, USA
| | - Yanglin Zhu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70018, USA
| | - Alyssa Chuang
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70018, USA
| | - D. Graf
- National High Magnetic Field Lab, Tallahassee, FL 32310, USA
| | - D. J. Adams
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148, USA
| | - S. M. A. Radmanesh
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148, USA
| | - L. Spinu
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148, USA
| | - I. Chiorescu
- National High Magnetic Field Lab, Tallahassee, FL 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
| | - Zhiqiang Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70018, USA
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Hu J, Liu JY, Graf D, Radmanesh SMA, Adams DJ, Chuang A, Wang Y, Chiorescu I, Wei J, Spinu L, Mao ZQ. π Berry phase and Zeeman splitting of Weyl semimetal TaP. Sci Rep 2016; 6:18674. [PMID: 26726050 PMCID: PMC4698660 DOI: 10.1038/srep18674] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [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: 08/24/2015] [Accepted: 11/23/2015] [Indexed: 11/28/2022] Open
Abstract
The recent breakthrough in the discovery of Weyl fermions in monopnictide semimetals provides opportunities to explore the exotic properties of relativistic fermions in condensed matter. The chiral anomaly-induced negative magnetoresistance and π Berry phase are two fundamental transport properties associated with the topological characteristics of Weyl semimetals. Since monopnictide semimetals are multiple-band systems, resolving clear Berry phase for each Fermi pocket remains a challenge. Here we report the determination of Berry phases of multiple Fermi pockets of Weyl semimetal TaP through high field quantum transport measurements. We show our TaP single crystal has the signatures of a Weyl state, including light effective quasiparticle masses, ultrahigh carrier mobility, as well as negative longitudinal magnetoresistance. Furthermore, we have generalized the Lifshitz-Kosevich formula for multiple-band Shubnikov-de Haas (SdH) oscillations and extracted the Berry phases of π for multiple Fermi pockets in TaP through the direct fits of the modified LK formula to the SdH oscillations. In high fields, we also probed signatures of Zeeman splitting, from which the Landé g-factor is extracted.
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Affiliation(s)
- J. Hu
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - J. Y. Liu
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - D. Graf
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - S. M. A. Radmanesh
- Advanced Materials Research Institute and Department of Physics, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - D. J. Adams
- Advanced Materials Research Institute and Department of Physics, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - A. Chuang
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - Y. Wang
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - I. Chiorescu
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - J. Wei
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - L. Spinu
- Advanced Materials Research Institute and Department of Physics, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Z. Q. Mao
- Department of physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA
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