Article
Materials Science, Multidisciplinary
Jukka Vayrynen, Moshe Goldstein, Yuval Gefen
Summary: The edges of quantum Hall phases exhibit a variety of exotic modes, including neutralons, which are chargeless anyons with semion statistics. These neutral particles can be experimentally accessed, making their study and manipulation intriguing and challenging. This article focuses on the strongly interacting regime of neutralons, where a quarteting mechanism replaces conventional pairing and leads to neutralon superconductivity. The manifestations of this effect are discussed, along with the potential for observing interference of the accompanying charged anyons.
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
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
Multidisciplinary Sciences
T. -W. Zhou, G. Cappellini, D. Tusi, L. Franchi, J. Parravicini, C. Repellin, S. Greschner, M. Inguscio, T. Giamarchi, M. Filippone, J. Catani, L. Fallani
Summary: The Hall effect, which describes the motion of charged particles in magnetic fields, has important implications for material properties. Understanding this effect in interacting systems is challenging, even for small magnetic fields. In this study, we used an atomic quantum simulator to investigate the behavior of ultracold fermions in the presence of artificial magnetic fields. Through experimental measurements, we observed a universal behavior of the Hall response, which is independent of the strength of atomic interactions. This research demonstrates the capability of quantum simulation to describe strongly correlated topological states of matter.
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)
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
Udit Khanna, Moshe Goldstein, Yuval Gefen
Summary: In this study, it is found that in certain situations, edge reconstruction can lead to the emergence of paired counterpropagating modes and may give rise to non-topological upstream neutral modes. This finding may explain the experimental observation of ubiquitous neutral modes and the suppression of anyonic interference in interferometry experiments.
PHYSICAL REVIEW LETTERS
(2022)
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
Optics
Christian Anker Rosiek, Guillermo Arregui, Anastasiia Vladimirova, Marcus Albrechtsen, Babak Vosoughi Lahijani, Rasmus Ellebaek Christiansen, Soren Stobbe
Summary: This study investigates the practical value of topological protection in reciprocal photonics. Measurements of propagation losses in valley-Hall topological waveguides in the slow-light regime show no evidence of topological protection against backscattering on structural defects. Light's unique properties support the development of photonic quantum technologies, optical interconnects, and novel sensors, but losses due to absorption or backscattering are a key limitation.
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
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
Physics, Multidisciplinary
G. Le Breton, R. Delagrange, Y. Hong, M. Garg, K. Watanabe, T. Taniguchi, R. Ribeiro-Palau, P. Roulleau, P. Roche, F. D. Parmentier
Summary: This study demonstrates the thermal equilibrium between integer channels and fractional channels in quantum Hall states of graphene. The results reveal markedly different regimes of quantized heat transport depending on edge electrostatics, providing a better understanding of the complex edge physics in the fractional quantum Hall regime.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Wei-Lin Mu, Xiao-Xuan Li, Xiao-Qiang Shao
Summary: We propose a cooling scheme to prepare stationary entanglement of neutral atoms in the Rydberg blockade regime by the combination of periodically collective laser pumping and dissipation. This protocol aims to stabilize the system into the desired steady state independently of the initial state, without requiring coherent addressing of individual neutral atoms or fine control of Rydberg interaction intensity, thus improving the feasibility of experiments in related fields.
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
Multidisciplinary Sciences
Ravi Kumar, Saurabh Kumar Srivastav, Christian Spanslatt, K. Watanabe, T. Taniguchi, Yuval Gefen, Alexander D. Mirlin, Anindya Das
Summary: Graphene has recently been used as a new platform for studying quantum Hall states. Noise measurements have provided evidence for the presence and ballistic nature of the upstream mode in the hole-conjugate fractional quantum Hall state in bilayer graphene. The existence of upstream modes moving against the charge current flow direction is crucial for the emergence of renormalized modes with exotic quantum statistics, with excess noise at the edge serving as a smoking gun for their presence.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Bivas Dutta, Wenmin Yang, Ron Melcer, Hemanta Kumar Kundu, Moty Heiblum, Vladimir Umansky, Yuval Oreg, Ady Stern, David Mross
Summary: Quantum Hall states have unique quantum phases characterized by gapless edge modes. The most studied nonabelian state is the spin-polarized filling factor 5/2, which can have different topological orders. By interfacing this state with another, we were able to identify its topological order as the particle-hole Pfaffian (PH-Pf) order.
Article
Physics, Applied
Prakiran Baidya, Vivas Bagwe, Pratap Raychaudhuri, Aveek Bid
Summary: A study of charge carrier dynamics in a novel two-dimensional superconducting van der Waals heterostructure reveals a percolative superconducting transition and non-Gaussian components indicative of long-range correlation.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Jehyun Kim, Jonginn Yun, Wonjin Jang, Hyeongyu Jang, Jaemin Park, Younguk Song, Min-Kyun Cho, Sangwoo Sim, Hanseo Sohn, Hwanchul Jung, Vladimir Umansky, Dohun Kim
Summary: In this study, we report energy-selective tunneling readout-based Hamiltonian parameter estimation of a two-electron spin qubit in a GaAs quantum dot array. By optimizing the readout fidelity, we achieved an average single-shot measurement time of 16 μs, along with adaptive initialization and efficient qubit frequency estimation based on realtime Bayesian inference. We observed a 40-fold increase in coherence time for qubit operation in a frequency heralded mode, without resorting to dynamic nuclear polarization. Additionally, we demonstrated active frequency feedback with quantum oscillation visibility, single-shot measurement fidelity, and gate fidelity of 97.7%, 99%, and 99.6%, respectively, showcasing the improvements in the overall capabilities of GaAs-based spin qubits. Pushing the sensitivity of energy-selective tunneling-based spin to charge conversion to the limit, this technique is useful for advanced quantum control protocols such as error mitigation schemes, where fast qubit parameter calibration with a high signal-to-noise ratio is crucial.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Subhradeep Misra, Michael Stern, Vladimir Umansky, Israel Bar-Joseph
Summary: This study demonstrates the characteristics and dynamics of Bose-Einstein condensation of dark excitons in GaAs coupled quantum wells at low temperatures. The results show that the condensate extends spatially beyond the optical excitation region and its density is determined by spin-flipping collisions among the excitons. The interaction between bright excitons and the condensate leads to its depletion.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Materials Science, Biomaterials
Abhijit Chandra Roy, Navin Kumar, Shreyas Bangalore Subramanya, Ananya Gupta, Aloke Kumar, Aveek Bid, Venkatakrishnan Venkataraman
Summary: This article introduces a 3D printable large-area electronic skin capable of sensing touch and load with extreme sensitivity, long-term stability, and cost-effectiveness. By using a uniquely designed optical waveguide and a layer of soft membrane, this electronic skin can function under various conditions.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Sourav Biswas, Rajarshi Bhattacharyya, Hemanta Kumar Kundu, Ankur Das, Moty Heiblum, Vladimir Umansky, Moshe Goldstein, Yuval Gefen
Summary: The fractional charge of quasiparticles is a fundamental feature of quantum Hall effect states. At sufficiently low temperatures, the Fano factor is found to be equal to the bulk filling factor, and this noise pattern is also observed on intermediate conductance plateaux.
Article
Physics, Multidisciplinary
Kazi Rafsanjani Amin, Ramya Nagarajan, Rahul Pandit, Aveek Bid
Summary: We present the first experimental evidence for the multifractality of a transport property at a topological phase transition. We show that conductance fluctuations display multifractality at the integer quantum Hall plateau-to-plateau transitions in high-mobility mesoscopic graphene devices, and this feature is rapidly suppressed as the chemical potential moves away from these critical points.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Bivas Dutta, Vladimir Umansky, Mitali Banerjee, Moty Heiblum
Summary: This study gapped out the integer modes by interfacing the nu = 5/2 state with integer states nu = 2 and nu = 3, and measured the thermal conductance of the isolated-interface channel. The measured half-quantized thermal conductance confirms the non-abelian nature of the nu = 5/2 state and its particle-hole Pfaffian topological order.
Article
Nanoscience & Nanotechnology
Priya Tiwari, Mohit Kumar Jat, Adithi Udupa, Deepa S. Narang, Kenji Watanabe, Takashi Taniguchi, Diptiman Sen, Aveek Bid
Summary: This research article reports the experimental determination of the band structure of single-layer graphene (SLG) in the presence of proximity-induced spin-orbit coupling. The study finds clear spin-splitting of the graphene bands and a substantial increase in the Fermi velocity. Theoretical modeling and analysis further reveal evidence of a band gap opening and band inversion. The study fills a gap in the quantitative measurement of the spin-splitting and low-energy dispersion relation in SLG.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Physics, Multidisciplinary
Ron Aharon Melcer, Sofia Konyzheva, Moty Heiblum, Vladimir Umansky
Summary: Thermal conductance measurements are crucial in condensed-matter physics for understanding topological order in two-dimensional topological insulators. A new local power measurement technique is presented to reveal the topological thermal Hall conductance, going beyond traditional two-terminal conductance measurements. This technique also proves useful in studying power carried by current fluctuations of partitioned edge modes with out-of-equilibrium distributions.
Article
Physics, Multidisciplinary
Hemanta Kumar Kundu, Sourav Biswas, Nissim Ofek, Vladimir Umansky, Moty Heiblum
Summary: In this article, the authors demonstrate the interference and braiding of anyons in a Mach-Zehnder interferometer, proving that this device is a powerful tool for probing the quantum statistics of anyonic fractional quantum Hall states.
Article
Physics, Applied
Ramya Nagarajan, Ranjan Kumar Patel, Aveek Bid
Summary: The study of phase transitions is crucial for understanding material physics and technological applications. This article analyzes the electronic transport properties of high entropy oxide thin films and observes an increase in resistance fluctuations during a first-order phase transition. The noise is found to be caused by an electronic phase separation and the formation of domains with localized and delocalized charges. This study establishes the presence of multiple states with similar energy levels in complex oxide thin films.
APPLIED PHYSICS LETTERS
(2023)
Article
Quantum Science & Technology
Jonginn Yun, Jaemin Park, Hyeongyu Jang, Jehyun Kim, Wonjin Jang, Younguk Song, Min-Kyun Cho, Hanseo Sohn, Hwanchul Jung, Vladimir Umansky, Dohun Kim
Summary: We demonstrate the simultaneous operation and measurement of two-electron spin qubits, decoupled from nuclear noise, in a GaAs quadruple quantum dot array. Coherent Rabi oscillations of both qubits are achieved by tuning their drive frequency using real-time Hamiltonian estimators. Strong two-qubit capacitive interaction and state-conditional frequency shift are observed, consistent with theoretical predictions. The high coherence to conditional phase-flip time ratio suggests the potential for generating high-fidelity and fast quantum entanglement using a simple capacitive interaction.
NPJ QUANTUM INFORMATION
(2023)
Article
Chemistry, Multidisciplinary
Priya Tiwari, Divya Sahani, Atasi Chakraborty, Kamal Das, Kenji Watanabe, Takashi Taniguchi, Amit Agarwal, Aveek Bid
Summary: In this study, the experimental evidence of the time-reversal symmetric Hall effect in high-mobility graphene-WSe2 heterostructures is provided. This dissipative Hall effect is linear and its sign depends on the charge carriers. It persists up to room temperature and can be tuned using an external electric field. The strain induced by lattice mismatch or alignment angle inhomogeneity breaks the inversion symmetry and produces anisotropic bands in graphene, leading to the appearance of a time-reversal symmetric Hall effect.
Article
Materials Science, Multidisciplinary
S. Sruthi, Deepa S. Narang, Prasad Vishnubhotla, Arnab Bera, Sk Kalimuddin, Kenji Watanabe, Takashi Taniguchi, Mintu Mondal, Aveek Bid
Summary: In this paper, we investigate the resistance fluctuations near the Lifshitz transition in WTe2 devices and identify the Lifshitz transition from electrical and thermal transport studies. Our study reveals the effect of interband scattering on the physics of Weyl semimetals through band structure analysis and electrical noise measurements.
