Article
Physics, Multidisciplinary
Bruno Nachtergaele, Simone Warzel, Amanda Young
Summary: The ground-state of a truncated version of Haldane's pseudo-potential Hamiltonian in the thin cylinder geometry is found to be composed of exponentially many fragmented matrix product states. These states, constructed by lattice tilings, exhibit specific properties and a spectral gap is proven, implying incompressibility of the underlying fractional quantum Hall liquid at maximal filling nu = 1/3. Additionally, low-energy excitations and an extensive number of many-body scars at positive energy density, but with low complexity, are identified using the concept of tilings.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Songyang Pu, Ajit C. Balram, Mikael Fremling, Andrey Gromov, Zlatko Papic
Summary: In the long-wavelength limit, supersymmetry (SUSY) describes the relationship between the two collective modes of the Moore-Read state in the fractional quantum Hall effect at filling factor v = 5/2. By constructing wave functions and conducting large-scale numerical simulations, we demonstrate the equivalence between SUSY wave functions and previous descriptions of collective modes based on the Girvin-MacDonald-Platzman ansatz, Jack polynomials, and bipartite composite fermions in the long-wavelength limit. Studying the energies of SUSY wave functions, we find that realistic v = 5/2 systems are close to the putative SUSY point, where the two collective modes become degenerate in energy.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Chengyu Wang, A. Gupta, S. K. Singh, Y. J. Chung, L. N. Pfeiffer, K. W. West, K. W. Baldwin, R. Winkler, M. Shayegan
Summary: In this study, a new and unexpected even-denominator FQHS was observed in a high-quality GaAs 2D hole system at filling factor v = 3/4. This FQHS is observed in the lowest Landau level and exhibits non-Abelian characteristics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Bartholomew Andrews, Madhav Mohan, Titus Neupert
Summary: Determining the statistics of elementary excitations supported by fractional quantum Hall states is crucial for understanding their properties and potential applications. The use of topological entanglement entropy to investigate single-component nu = 2/5 and 3/7 states in the Hofstadter model reveals Abelian topological order. Many-body simulations using the infinite cylinder density matrix renormalization group were conducted, presenting an efficient algorithm to construct the area law of entanglement.
Article
Nanoscience & Nanotechnology
Binghao Guo, Alexander C. C. Lygo, Xi Dai, Susanne Stemmer
Summary: In this study, the observation of a quantum Hall state with a filling factor of zero in a thin film cadmium arsenide sample tuned by a gate voltage is reported, and possible mechanisms underlying this phenomenon are discussed.
Article
Physics, Mathematical
Bruno Nachtergaele, Simone Warzel, Amanda Young
Summary: The study explores an effective Hamiltonian for the standard nu=1/3 fractional quantum Hall system in the thin cylinder regime. It provides a complete description of the ground state space using Fragmented Matrix Product States and proves the existence of a spectral gap above the ground states for a range of coupling constants, establishing the incompressibility of the fractional quantum Hall states. Additionally, it shows that all ground states labeled by a tiling have a finite correlation length, with an upper bound given. However, it is demonstrated through an example that not all superpositions of tiling states exhibit exponential decay of correlations.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Tian-Sheng Zeng, Liangdong Hu, W. Zhu
Summary: This study explores the topological phases of two-component hardcore bosons and reveals important topological features, such as the degeneracy of the ground state and the presence of chiral edge modes.
CHINESE PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Tongzhou Zhao, William N. Faugno, Songyang Pu, Ajit C. Balram, J. K. Jain
Summary: A three-dimensional fixed-phase diffusion Monte Carlo method was developed to study the nature of the fractional quantum Hall effect at nu = 1/2 in wide quantum wells, including Landau level mixing. The calculations found that the one-component composite-fermion Fermi sea and the one-component Pfaffian states are very close in energy, suggesting that the observed 1/2 state in wide quantum wells is likely the one-component Pfaffian state. Further experimental studies of this state are encouraged.
Article
Materials Science, Multidisciplinary
Takuya Ito, Naokazu Shibata
Summary: The study focused on the edge states in fractional quantum Hall systems at filling factor nu = 1/3 using the density matrix renormalization group method. It was found that the density oscillation induced by local boundary conditions and the wave number of the minimum magnetoroton excitation play a key role in characterizing the edge structure. Additionally, changes in the confinement potential shape can lead to a partial reconstruction of this structure, while the stability of bulk states against variations in the number of electrons highlights the incompressibility of the bulk part of the fractional quantum Hall state.
Article
Physics, Multidisciplinary
Ha Quang Trung, Bo Yang
Summary: By studying low-lying excitations at filling factor nu = n + 1/3 with realistic interactions, it is found that they can be understood as quantum fluids with Gaffnian quasiholes, instead of Laughlin quasiparticles. Near the experimentally observed nematic FQH phase in higher Landau levels, quasiholes become weakly bound and exhibit rich dynamical properties. It is predicted that a finite temperature phase transition of Laughlin quasiholes can occur even when the Laughlin ground state remains incompressible, providing relevant experimental conditions for potential observations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Ajit C. Balram
Summary: The study focuses on the fractional quantum Hall effect at the filling factor nu = 4/11, identifying a plausible ground state described by the 4 (2) over bar1(3) parton wave function. Predictions are made for experimentally measurable properties of this state based on the low-energy effective theory of the 4 (2) over bar1(3) edge.
Article
Physics, Multidisciplinary
J. Nakamura, S. Liang, G. C. Gardner, M. J. Manfra
Summary: Electronic Fabry-Perot interferometry is a powerful method for probing quasiparticle charge and anyonic braiding statistics in the fractional quantum Hall regime. In the v = 2/5 fractional quantum Hall state, we observe two interfered independently edge modes. The outer mode behaves similarly to the v = 1/3 state, while the inner mode shows discrete phase jumps indicative of distinct anyonic braiding statistics.
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
Koyena Bose, Ajit C. Balram
Summary: This article discusses the possibility of stabilizing non-Abelian topological orders in the fractional quantum Hall effect (FQHE) in the second Landau level (SLL). A parton sequence is proposed to describe the observed fractions in the SLL. By studying the first member of this sequence at 4/11, which has not been experimentally observed yet, we find that it might be a viable non-Abelian state and make predictions for experimentally measurable properties that can distinguish it from other topological orders.
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
Physics, Multidisciplinary
Ahmet Demir, Neal Staley, Samuel Aronson, Spencer Tomarken, Ken West, Kirk Baldwin, Loren Pfeiffer, Raymond Ashoori
Summary: This research utilized laterally large and low-disorder GaAs quantum-well-based quantum dots to study tunneling of single electrons, identifying single-electron capacitance peaks in the addition spectrum. Two remarkable phenomena were observed in the Landau level filling factor range of nu = 2 to nu = 5: Coulomb blockade peaks due to the entrance of two electrons instead of one, and uniform appearance of double-height peaks at and near nu = 5/2 with a magnetic field flux periodicity of h/2e.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Md S. Hossain, M. K. Ma, K. A. Villegas-Rosales, Y. J. Chung, L. N. Pfeiffer, K. W. West, K. W. Baldwin, M. Shayegan
Summary: This study demonstrates the ability to control valley polarization in a two-dimensional electron system through gate bias, explaining that the phenomenon arises from electron-electron interaction. Furthermore, the researchers found that the valley polarization transition is accompanied by a sudden change in sample resistance, which is of interest for potential valleytronic transistor device applications.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Camille Lagoin, Stephan Suffit, Kirk Baldwin, Loren Pfeiffer, Francois Dubin
Summary: In this research, the existence of a Mott phase was observed by exploring the Bose-Hubbard model with semiconductor excitons confined in a two-dimensional lattice. This provides a potential pathway for studying many-body phases that break lattice symmetry.
Article
Physics, Multidisciplinary
Yoon Jang Chung, D. Graf, L. W. Engel, K. A. Villegas Rosales, P. T. Madathil, K. W. Baldwin, K. W. West, L. N. Pfeiffer, M. Shayegan
Summary: This study investigates the ground state of two-dimensional electron systems (2DESs) at low Landau level filling factors using improved experimental methods. It confirms the existence of fractional quantum Hall states that comply with the Jain sequence even in the extremely low Landau level filling limit.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Ziyu Liu, Ursula Wurstbauer, Lingjie Du, Ken W. West, Loren N. Pfeiffer, Michael J. Manfra, Aron Pinczuk
Summary: This study investigates the impacts of domain textures on low-lying neutral excitations in bulk fractional quantum Hall effect (FQHE) systems using resonant inelastic light scattering. The research demonstrates that large domains of quantum fluids support long-wavelength neutral collective excitations with well-defined wave vector dispersion, which can be explained by theories for uniform phases. The accessibility of dispersive low-lying neutral collective modes, such as long wavelength magnetorotons at filling factor v = 1/3, in large domains of FQHE fluids offers significant experimental access to strong electron correlation physics in the FQHE.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
V Ardizzone, F. Riminucci, S. Zanotti, A. Gianfrate, M. Efthymiou-Tsironi, D. G. Suarez-Forero, F. Todisco, M. De Giorgi, D. Trypogeorgos, G. Gigli, K. Baldwin, L. Pfeiffer, D. Ballarini, H. S. Nguyen, D. Gerace, D. Sanvitto
Summary: This study discovered bound states in the continuum (BICs) in a planar photonic crystal lattice, which have a long lifetime and are not affected by radiation. The researchers also demonstrated non-equilibrium Bose-Einstein condensation occurring in the BIC. By combining bosonic condensation and symmetry-protected radiation eigenmodes, they showed a way to impart topological properties onto macroscopic quantum states.
Article
Materials Science, Multidisciplinary
Yoon Jang Chung, C. Wang, S. K. Singh, A. Gupta, K. W. Baldwin, K. W. West, M. Shayegan, L. N. Pfeiffer, R. Winkler
Summary: This paper reports the fabrication of ultra-high-quality (001) GaAs 2D hole systems with significantly improved mobility values. High-order fractional quantum Hall states and a deep minimum in the magnetoresistance were observed in the measurements.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Applied
C. Hnatovsky, M. A. Zudov, G. D. Austing, A. Bogan, S. J. Mihailov, M. Hilke, K. W. West, L. N. Pfeiffer, S. A. Studenikin
Summary: This paper proposes a non-destructive, all-optical technique to create embedded lateral superlattices near semiconductor heterostructures by illuminating the samples with a stable interference pattern. The technique is demonstrated on a GaAs/A1GaAs sample with Si delta-doping by inducing charge redistribution in the doping layer. The characteristics of the light-induced superlattice are obtained through the analysis of Weiss commensurability oscillations in the magnetoresistance.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Condensed Matter
Haoyun Huang, S. A. Myers, L. N. Pfeiffer, K. W. West, K. W. Baldwin, G. A. Csathy
Summary: This study reports on the large signal current-voltage characteristics measurements near the v = 1 integer quantum Hall plateau in a high mobility GaAs/AlGaAs sample. The research finds that both the Anderson insulator and integer quantum Hall Wigner solid exhibit a sharp onset of conduction at low temperatures and under large bias currents, with this onset depending monotonically on the filling factor across the boundary between the two localized phases. Surprisingly, these large signal characteristics do not clearly differentiate between the Anderson insulator and the integer quantum Hall Wigner solid.
SOLID STATE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Md Shafayat Hossain, Meng K. Ma, Y. J. Chung, S. K. Singh, A. Gupta, K. W. West, K. W. Baldwin, L. N. Pfeiffer, R. Winkler, M. Shayegan
Summary: This study demonstrates how the valley degree of freedom impacts the fractional quantum states (FQHSs) through magnetotransport experiments. The researchers find a surprisingly robust ferromagnetism of the FQHSs and the underlying composite fermions (CFs), suggesting a strong interaction between the CFs in the system.
Article
Materials Science, Multidisciplinary
Q. Yao, E. Sedov, S. Mukherjee, J. Beaumariage, B. Ozden, K. West, L. Pfeiffer, A. Kavokin, D. W. Snoke
Summary: This study presents observations of a nonequilibrium polariton condensate injected in a quasi-1D ring, revealing the existence of circular polarization precession and the influence of zitterbewegung behavior on the motion of polaritons.
Article
Materials Science, Multidisciplinary
Xinghao Wang, Peizhe Jia, Rui-Rui Du, L. N. Pfeiffer, K. W. Baldwin, K. W. West
Summary: This article systematically studies the behavior of viscous fluid in an ultrahigh-mobility two-dimensional electron gas (2DEG) in GaAs/AlGaAs quantum wells through measurements of negative magnetoresistance (NMR) and photoresistance under microwave radiation, and analyzes the data according to recent theoretical work. The results show that the size-dependent and temperature-dependent NMR conform to the theoretical predictions, and the size dependence of microwave induced resistance oscillations and the second harmonic peak indicate that 2DEG in a moderate magnetic field can also be regarded as viscous fluid. The size-dependent radiation heating effect is found by using NMR as electron thermometry. These findings suggest that the hydrodynamic effects must be considered in order to understand semiclassical electronic transport in a clean 2DEG.
Article
Materials Science, Multidisciplinary
Yoon Jang Chung, A. Gupta, K. W. Baldwin, K. W. West, M. Shayegan, L. N. Pfeiffer
Summary: Ultrahigh-mobility GaAs two-dimensional electron systems (2DESs) have been a significant platform for condensed-matter physics research for several decades. Continuous improvement in sample quality has enabled scattering-free transport and led to the emergence of exotic many-body phenomena. Recent research shows the potential for further increasing the mobility limit of GaAs 2DESs, and discusses scenarios for achieving mobility values exceeding 100 x 10(6) cm(2)/Vs.
Article
Materials Science, Multidisciplinary
X. Fu, Q. Shi, M. A. Zudov, G. C. Gardner, J. D. Watson, M. J. Manfra, K. W. Baldwin, L. N. Pfeiffer, K. W. West
Summary: Anomalous nematic states, discovered in ultraclean two-dimensional electron gas, emerge from quantum Hall stripe phases upon further cooling. These states are characterized by specific resistance features in nearly half-filled Landau levels, and a modest in-plane magnetic field can destroy these states and restore quantum Hall stripe phases.
Article
Materials Science, Multidisciplinary
S. A. Myers, Haoyun Huang, L. N. Pfeiffer, K. W. West, G. A. Csathy
Summary: The study reveals the reentrant integer quantum Hall effect and the formation of the integer quantum Hall Wigner solid in a GaAs/AlGaAs sample with high electron mobility. Sharp peaks in the longitudinal resistance versus temperature were observed, suggesting a universal transport signature of isotropic electron solids. The study discusses the possible origins of these sharp resistance peaks and presents a stability diagram for the insulating phases in the nu-T phase space.
