Article
Physics, Multidisciplinary
Ke Huang, Hailong Fu, Danielle Reifsnyder Hickey, Nasim Alem, Xi Lin, Kenji Watanabe, Takashi Taniguchi, Jun Zhu
Summary: In this study, we investigate the control over valley isospin degrees of freedom in bilayer graphene using a perpendicular electric field. We observe a new even-denominator fractional quantum Hall state at filling factor v = 5/2 and the appearance of predicted daughter states and anti-Pfaffian states. These findings pave the way for manipulating valley isospin in bilayer graphene to engineer exotic topological orders and quantum information processes.
Article
Chemistry, Multidisciplinary
Bin Cao, Tobias Grass, Olivier Gazzano, Kishan Ashokbhai Patel, Jiuning Hu, Markus Muller, Tobias Huber-Loyola, Luca Anzi, Kenji Watanabe, Takashi Taniguchi, David B. Newell, Michael Gullans, Roman Sordan, Mohammad Hafezi, Glenn S. Solomon
Summary: By accurately measuring the photocurrent signal and modeling the data using optical Bloch equations, we have studied the relaxation of carriers in graphene in the quantum Hall regime. Our results provide a unified understanding of the relaxation processes in graphene over different magnetic field strength regimes and show clear evidence of carrier multiplication. Additionally, our findings reveal the interplay of Coulomb interactions and interactions with acoustic and optical phonons, as well as the chiral transport properties and chirality change at the Dirac point in the quantum Hall regime.
Article
Materials Science, Multidisciplinary
Sujit Narayanan, Malcolm P. Kennett
Summary: We study the collective excitations of fractional quantum Hall states in graphene, focusing on states allowing for chiral symmetry breaking orders, such as antiferromagnetism and charge density wave order. Numerical investigations are conducted to explore how the collective excitation spectra depend on filling and the flux attachment scheme for two classes of variational states, namely the Toke-Jain sequence and the Modak-Mandal-Sengupta sequence.
Article
Multidisciplinary Sciences
Ying Wang, Vadim Ponomarenko, Zhong Wan, Kenneth W. West, Kirk W. Baldwin, Loren N. Pfeiffer, Yuli Lyanda-Geller, Leonid P. Rokhinson
Summary: Experimental observation in the fractional quantum Hall regime shows that the current carried by hDWs is significantly smaller than predicted by the naive model. Theoretical analysis using Luttinger liquid theory reveals a redistribution of currents between quasiparticle charge, spin, and neutral modes, leading to the reduction of the hDW current. Including spin-non-conserving tunneling processes reconciles theory with experiment and confirms the emergence of spin modes necessary for the formation of fractional topological superconductivity.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Zhaoyu Han, Jing-Yuan Chen
Summary: We construct a class of lattice Hamiltonians that can be solved controllably in their low-energy sectors through a combination of perturbative and exact techniques, circumventing the KapustinFidkowski no-go theorem. Our construction is generalizable.
Article
Materials Science, Multidisciplinary
N. Moreau, B. Brun, S. Somanchi, K. Watanabe, T. Taniguchi, C. Stampfer, B. Hackens
Summary: Observations of electron-hole asymmetry in transport through graphene devices at high magnetic field challenge prevalent models of the graphene quantum Hall effect. The presence of upstream modes and local doping in the vicinity of electrical contacts leads to a different topological breakdown for electrons and holes, explaining the observed asymmetry.
Article
Physics, Condensed Matter
Xi Wu, M. A. Zubkov
Summary: An anomalous fractional quantum Hall effect is discussed, which can exist without an external magnetic field. It is proposed that excitations in such systems may be effectively described by non-interacting particles with Hamiltonians defined on the Brillouin zone with a branch cut. The Hall conductivity of this system is expressed through the one-particle Green function, and for the proposed type of Hamiltonians, this expression takes fractional values times the Klitzing constant. Possible relation of this construction with the degeneracy of the ground state is also discussed.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Review
Physics, Multidisciplinary
D. E. Feldman, Bertrand Halperin
Summary: This article discusses the key features of the fractional quantum Hall effect, focusing on quasiparticles with fractional charge and statistics. It provides detailed definitions and methods for observing these properties, along with a review of current experimental status and discussions on non-Abelian statistics. The attempts to find experimental evidence for non-Abelian quasiparticles in certain quantum Hall systems are also explored.
REPORTS ON PROGRESS IN PHYSICS
(2021)
Article
Multidisciplinary Sciences
I Taktak, M. Kapfer, J. Nath, P. Roulleau, M. Acciai, J. Splettstoesser, I Farrer, D. A. Ritchie, D. C. Glattli
Summary: In this study, a novel interferometric approach was used to demonstrate that anyons maintain quantum coherence while propagating. The results have positive implications for achieving controlled quantum coherent braiding of anyons.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Li Qing-Xin, Huang Yan, Chen Yi-Wei, Zhu Yu-Jian, Zhu Wang, Song Jun-Wei, An Dong-Dong, Gan Qi-Kang, Wang Kai-Yuan, Wang Hao-Lin, Mai Zhi-Hong, Andy Shen, Xi Chuan-Ying, Zhang Jing-Lei, Yu Ge-Liang, Wang Lei
Summary: In this study, the electric transport behavior of bilayer graphene under electric and magnetic fields was investigated using high-quality bilayer graphene/hBN heterostructure. The observed even-denominator fractional quantum Hall state exhibits non-Abelian statistics, indicating its potential for topological quantum computation.
ACTA PHYSICA SINICA
(2022)
Article
Chemistry, Multidisciplinary
Lingfei Zhao, Ethan G. Arnault, Trevyn F. Q. . Larson, Zubair Iftikhar, Andrew Seredinski, Tate Fleming, Kenji Watanabe, Takashi Taniguchi, Francois Amet, Gleb Finkelstein
Summary: The vanishing band gap of graphene has posed challenges for creating high-quality quantum point contacts. However, recent advances have allowed split-gate QPCs to operate using the highly resistive v = 0 state. Researchers have developed a simple method of fabricating QPCs by etching a narrow trench in the graphene sheet, separating the conducting channel from self-aligned graphene side gates. This technique has enabled the creation and study of a quantum Hall interferometer.
Article
Multidisciplinary Sciences
Jonathan Schirmer, C. -X. Liu, J. K. Jain
Summary: This article investigates the interplay between pairing and topological orders in a spin polarized electron system on a Hofstadter lattice. It shows that with increasing attractive interaction, the system undergoes phase transitions from a quantum Hall phase to a skyrmion lattice phase and then to a vortex phase. The experimental feasibility and observable consequences of skyrmions and Majorana modes are indicated.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Materials Science, Multidisciplinary
E. Peraticos, S. Kumar, M. Pepper, A. Siddiki, I. Farrer, D. Ritchie, G. Jones, J. Griffiths
Summary: We report experimental observations of hysteresis in the integer quantum Hall regime of a GaAs/AlGaAs heterostructure. The nonequilibrium processes arising from direct Coulomb interactions and the dissipative nature of the Hall bar, together with scattering-influenced contacts, are shown to be responsible for the observed anomalous effects. Hysteretic behavior is found for various filling factors, including both integer and fractional states.
Article
Physics, Multidisciplinary
Anirban Sharma, Songyang Pu, Ajit C. Balram, J. K. Jain
Summary: Motivated by the observation of even denominator fractional quantum Hall effect in the n = 3 Landau level of monolayer graphene, a Bardeen-Cooper-Schrieffer variational state for composite fermions is considered, leading to the finding that the composite-fermion Fermi sea in this Landau level is unstable to an f-wave pairing. Analogous calculations suggest the possibility of a p-wave pairing of composite fermions at half filling in the n = 2 graphene Landau level, while no pairing instability is found at half filling in the n = 0 and n = 1 graphene Landau levels. The relevance of these results to experiments is discussed.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jing-Yun Fang, Ning-Xuan Yang, Qing Yan, Ai-Min Guo, Qing-Feng Sun
Summary: The study reveals the presence of dissipation in topological systems, where thermal dissipation can occur in the quantum Hall regime in graphene. Dissipation processes are accompanied by the evolution of energy distribution from nonequilibrium to equilibrium.
Article
Materials Science, Multidisciplinary
Michael R. Peterson, Yang-Le Wu, Meng Cheng, Maissam Barkeshli, Zhenghan Wang, Sankar Das Sarma
Article
Physics, Multidisciplinary
Kiryl Pakrouski, Michael R. Peterson, Thierry Jolicoeur, Vito W. Scarola, Chetan Nayak, Matthias Troyer
Article
Materials Science, Multidisciplinary
Michael R. Peterson, Z. Papic, S. Das Sarma
Article
Materials Science, Multidisciplinary
V. W. Scarola, C. May, M. R. Peterson, M. Troyer
Article
Materials Science, Multidisciplinary
Michael R. Peterson, S. Das Sarma
Article
Materials Science, Multidisciplinary
Michael R. Peterson, B. Sriram Shastry
Article
Materials Science, Multidisciplinary
J. Biddle, Michael R. Peterson, S. Das Sarma
Article
Materials Science, Multidisciplinary
J. Biddle, Michael R. Peterson, S. Das Sarma
Article
Materials Science, Multidisciplinary
David C. Ronquillo, Michael R. Peterson
Article
Physics, Multidisciplinary
Michael R. Peterson, Chetan Nayak
PHYSICAL REVIEW LETTERS
(2014)
Article
Materials Science, Multidisciplinary
Eduardo Palacios, Michael R. Peterson
Summary: Particle-hole symmetry breaking in the lowest Landau level of the fractional quantum Hall effect under the influence of a finite magnetic field has been theoretically studied in this work. The analysis shows that while symmetry is broken between states related via particle-hole conjugation based on energy gaps, it is largely maintained as determined by the effective mass of composite fermions. These findings are connected to recent experimental observations regarding particle-hole symmetry in the lowest Landau-level fractional quantum Hall effect.
Article
Materials Science, Multidisciplinary
Michael Arciniaga, Michael R. Peterson
Article
Materials Science, Multidisciplinary
Kiryl Pakrouski, Matthias Troyer, Yang-Le Wu, Sankar Das Sarma, Michael R. Peterson
Proceedings Paper
Physics, Multidisciplinary
Michael R. Peterson
IUPAP C20 CONFERENCE ON COMPUTATIONAL PHYSICS (CCP 2011)
(2012)