English
Related papers

Related papers: Engineering Quantum Hall Phases in Synthetic Bilay…

200 papers

Quantum Hall effect (QHE), the ground to construct modern conceptual electronic systems with emerging physics, is often much influenced by the interplay between the host two-dimensional electron gases and the substrate, sometimes predicted…

We analyze the bilayer quantum Hall (QH) system by mapping it to the monolayer QH system with spin degrees of freedom. By this mapping the tunneling interaction term is identified with the Zeeman term. We clarify the mechanism of a…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Z. F. Ezawa

We consider the zero-filled quantum-Hall ferromagnetic state of bilayer graphene subject to a kink-like perpendicular electric field, which generates domain walls in the electronic state and low-energy collective modes confined to move…

Strongly Correlated Electrons · Physics 2015-06-17 Victoria Mazo , Chia-Wei Huang , Efrat Shimshoni , Sam T. Carr , H. A. Fertig

We develop a nonperturbative approach to the quantum Hall bilayer (QHB) at \nu=1 using trial wave functions. We predict phases of the QHB for arbitrary distance d and, our approach, in a dual picture, naturally introduces a new kind of…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 M. V. Milovanović , Z. Papić

We consider a number of strongly-correlated quantum Hall states which are likely to be realized in bilayer quantum Hall systems at total Landau level filling fraction ${\nu_T}=1$. One state, the $(3,3,-1)$ state, can occur as an instability…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yong Baek Kim , Chetan Nayak , Eugene Demler , N. Read , S. Das Sarma

Graphene enables precise carrier-density control via gating, making it an ideal platform for studying electronic interactions. However, sample inhomogeneities often limit access to the low-density regimes where these interactions dominate.…

We present a phase diagram for a double quantum well bilayer electron gas in the quantum Hall regime at total filling factor $\nu =1$, based on exact numerical calculations of the topological Chern number matrix and the (inter-layer)…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. N. Sheng , Leon Balents , Ziqiang Wang

Bilayer graphene (BLG) offers a rich platform for broken symmetry states stabilized by interactions. In this work we study the phase diagram of BLG in the quantum Hall regime at filling factor $\nu=0$ within the Hartree-Fock approximation.…

Strongly Correlated Electrons · Physics 2017-12-27 Ganpathy Murthy , Efrat Shimshoni , Herbert Fertig

Here we report from our theoretical studies that in biased bilayer graphene, one can induce phase transitions from an incompressible state to a compressible state by tuning the bandgap at a given electron density. Likewise, variation of the…

Materials Science · Physics 2010-03-02 Vadim M. Apalkov , Tapash Chakraborty

The zeroth Landau level (0LL) in graphene has emerged as a flat-band platform in which distinct many-body phases can be explored with unprecedented control by simply tuning the strength and/or direction of magnetic fields1-22. A rich set of…

Mesoscale and Nanoscale Physics · Physics 2021-12-23 Qi Zheng , Mo-Han Zhang , Ya-Ning Ren , Lin He

We re-examine the nature of the ground states of bilayer graphene at odd integer filling factors within a simplified model of nearly degenerate $n=0$ and $n=1$ Landau levels. Previous Hartree-Fock studies have found that ferroelectric…

Strongly Correlated Electrons · Physics 2019-04-03 Thierry Jolicoeur , Csaba Tőke , Inti Sodemann

Owing to their wide tunability, spin- and valley internal degrees of freedom, and low disorder, graphene heterostructures are emerging as a promising experimental platform for fractional quantum Hall (FQH) studies. Surprisingly, however,…

Strongly Correlated Electrons · Physics 2018-12-05 Hryhoriy Polshyn , Haoxin Zhou , Eric. M. Spanton , Takashi Taniguchi , Kenji Watanabe , Andrea F. Young

Strong interaction between electrons in two-dimensional systems in the presence of a high magnetic field gives rise to fractional quantum Hall states that host quasiparticles with fractional charge and fractional exchange statistics. Here,…

An improved composite-boson theory of quantum Hall ferromagnets is formulated both for the monolayer and bilayer systems. In this scheme the field operator describes solely the physical degrees of freedom representing the deviation from the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Z. F. Ezawa

Equilibration of quantum Hall edges is studied in a high quality dual gated bilayer graphene device in both unipolar and bipolar regime when all the degeneracies of the zero energy Landau level are completely lifted. We find that in the…

Mesoscale and Nanoscale Physics · Physics 2018-10-24 Chandan Kumar , Saurabh Kumar Srivastav , Anindya Das

Bilayer graphene has a unique electronic structure influenced by a complex interplay between various degrees of freedom. We probe its chemical potential using double bilayer graphene heterostructures, separated by a hexagonal boron nitride…

Mesoscale and Nanoscale Physics · Physics 2014-07-08 Kayoung Lee , Babak Fallahazad , Jiamin Xue , David C. Dillen , Kyounghwan Kim , Takashi Taniguchi , Kenji Watanabe , Emanuel Tutuc

The quantum Hall effect near the charge neutrality point in bilayer graphene is investigated in high magnetic fields of up to 35 T using electronic transport measurements. In the high field regime, the eight-fold degeneracy in the zero…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Y. Zhao , P. Cadden-Zimansky , Z. Jiang , P. Kim

Owing to the spin, valley, and orbital symmetries, the lowest Landau level (LL) in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer and fractional…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 Yanmeng Shi , Yongjin Lee , Shi Che , Ziqi Pi , Timothy Espiritu , Petr Stepanov , Dmitry Smirnov , Chun Ning Lau , Fan Zhang

We examine the quantum phase diagram of the fractional quantum Hall effect in the lowest Landau level in half-filled bilayer structures as a function of tunneling strength and layer separation. Using numerical exact diagonalization we…

Mesoscale and Nanoscale Physics · Physics 2009-10-23 S. Das Sarma , Michael R. Peterson

Recent experiments on twisted bilayer graphene show an anomalous quantum Hall (AQH) effect at filling of $3$ electrons per moir\`e unit cell. The AQH effect arises in an insulating state with both valley- and ferromagnetic order. We argue,…

Strongly Correlated Electrons · Physics 2020-09-30 Thomas Bömerich , Lukas Heinen , Achim Rosch