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Related papers: Quantum-criticality in twisted bi-layer graphene

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We study the effect of electron-acoustic phonon interactions in twisted bilayer graphene on resistivity in the high-temperature transport and superconductivity in the low-temperature phase diagram. We theoretically show that twisted bilayer…

Mesoscale and Nanoscale Physics · Physics 2019-04-10 Fengcheng Wu , Euyheon Hwang , Sankar Das Sarma

Twisted bilayer graphene is an exciting platform for exploring correlated quantum phases, extremely tunable with respect to both the single-particle bands and the interaction profile of electrons. Here, we investigate the phase diagram of…

Strongly Correlated Electrons · Physics 2023-12-08 Nikita Astrakhantsev , Glenn Wagner , Tom Westerhout , Titus Neupert , Mark H. Fischer

2D materials based superlattices have emerged as a promising platform to modulate band structure and its symmetries. In particular, moir\'e periodicity in twisted graphene systems produces flat Chern bands. The recent observation of…

We report an observation of quantum oscillations (QOs) in the correlated insulators with valley anisotropy of twisted double bilayer graphene (TDBG). The anomalous QOs are best captured in the magneto resistivity oscillations of the…

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the…

Mesoscale and Nanoscale Physics · Physics 2020-09-04 Pietro Novelli , Iacopo Torre , Frank H. L. Koppens , Fabio Taddei , Marco Polini

The dominance of Coulomb interactions over kinetic energy of electrons in narrow, non-trivial moir\'{e} bands of magic-angle twisted bilayer graphene (TBG) gives rise to a variety of correlated phases such as correlated insulators,…

The study of higher-order and real topological states as well as the material realization have become a research forefront of topological condensed matter physics in recent years. Twisted bilayer graphene (tbG) is proved to have…

Materials Science · Physics 2022-08-02 Bin-Bin Liu , Xu-Tao Zeng , Cong Chen , Ziyu Chen , Xian-Lei Sheng

Large-angle twisted bilayer graphene (tBLG) is known to be electronically decoupled due to the spatial separation of the Dirac cones corresponding to individual graphene layers in the reciprocal space. The close spacing between the layers…

Mesoscale and Nanoscale Physics · Physics 2023-02-28 Alina Mrenca-Kolasinska , Peter Rickhaus , Giulia Zheng , Klaus Richter , Thomas Ihn , Klaus Ensslin , Ming-Hao Liu

Two-dimensional materials (2DMs) are fundamentally electro-mechanical systems. Their environment unavoidably strains them and modifies their quantum transport properties. For instance, a simple uniaxial strain could completely turn off the…

Mesoscale and Nanoscale Physics · Physics 2024-04-30 A. C. McRae , G. Wei , L. Huang , S. Yigen , V. Tayari , A. R. Champagne

The in-plane DC conductivity of twisted bilayer graphene (TBLG) is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding (TB) approach the transport…

Mesoscale and Nanoscale Physics · Physics 2018-03-28 M. Anđelković , L. Covaci , F. M. Peeters

Topological Mott insulator (TMI) with spontaneous time-reversal symmetry breaking and nonzero Chern number has been discovered in a real-space effective model for twisted bilayer graphene (TBG) at 3/4 filling in the strong coupling limit.…

Strongly Correlated Electrons · Physics 2022-05-26 Xiyue Lin , Bin-Bin Chen , Wei Li , Zi Yang Meng , Tao Shi

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. It is being discussed in a number of strongly correlated electron systems. A prototype case occurs in the…

Strongly Correlated Electrons · Physics 2011-02-28 Qimiao Si

In magic angle twisted bilayer graphene, transport, thermodynamic and spectroscopic experiments pinpoint at a competition between distinct low-energy states with and without electronic order. We use Dynamical Mean Field Theory (DMFT) on the…

Flat electronic bands can accommodate a plethora of interaction driven quantum phases, since kinetic energy is quenched therein and electronic interactions therefore prevail. Twisted bilayer graphene, near so-called the "magic angles",…

Mesoscale and Nanoscale Physics · Physics 2019-03-27 Bitan Roy , Vladimir Juricic

Using the semiclassical quantum Boltzmann theory and employing the Dirac model with twist angle-dependent Fermi velocity we obtain results for the electrical resistivity, the electronic thermal resistivity, the Seebeck coefficient, and the…

Mesoscale and Nanoscale Physics · Physics 2020-01-22 Mohammad Zarenia , Indra Yudishtira , Shaffique Adam , Giovanni Vignale

Graphene and its multilayers have attracted considerable interest owing to the fourfold spin and valley degeneracy of their charge carriers, which enables the formation of a rich variety of broken-symmetry states and raises the prospect of…

Mesoscale and Nanoscale Physics · Physics 2013-09-10 Benjamin E. Feldman , Andrei J. Levin , Benjamin Krauss , Dmitry Abanin , Bertrand. I. Halperin , Jurgen H. Smet , Amir Yacoby

We study fermions at quantum criticality with extremely retarded interactions of the form $V(\omega_l)=(g/|\omega_l|)^\gamma$, where $\omega_l$ is the transferred Matsubara frequency. This system undergoes a normal-superconductor phase…

Superconductivity · Physics 2022-08-30 Emil A. Yuzbashyan , Michael K. -H. Kiessling , Boris L. Altshuler

Strongly correlated phases in twisted bilayer graphene (TBG) typically arise as transitions from a state in which the system behaves as a normal metal. In such metallic regime, electron-electron interactions usually only play a subleading…

Mesoscale and Nanoscale Physics · Physics 2023-10-17 Federico Escudero , Juan Sebastián Ardenghi

The discovery of alternating superconducting and insulating ground-states in magic angle graphene has suggested an intriguing analogy with cuprate high-$T_c$ materials. Here we argue that the network states of small angle twisted bilayer…

Strongly Correlated Electrons · Physics 2020-10-02 E. J. König , Piers Coleman , A. M. Tsvelik

The tetragonal heavy-fermion metal YbRh$_2$Si$_2$ orders antiferromagnetically at $T_{\rm N} = 70$ mK and exhibits an unconventional quantum critical point (QCP) of Kondo-destroying type at $B_{\rm N} = 60$ mT, for the magnetic field…

Superconductivity · Physics 2022-04-28 Erwin Schuberth , S. Wirth , F. Steglich