CMSP Group announces seminar on Thursday

[Cond.Matt. & Stat.Mech.Section]

Seminar  on  Disorder and strong electron correlations



Thursday, 5 December -  11:30 a.m.

 

Luigi Stasi Seminar Room,  Leonardo Building - first floor


 

Vladimir FALKO    ( Lancaster University )



"Moiré minibands in van der Waals heterostructures of graphene with hexagonal crystals"



Abstract

 

The technological development of graphene has generated new high-quality systems offer access to the earlier inaccessible extremes of quantum physics. When graphene is placed on an atomically flat substrate with hexagonal lattice with a close lattice constant, such as boron nitride (hBN), and their crystalline axes are aligned, a long-wavelength perfectly periodic moiré pattern forms for electrons in graphene. In this talk, various regimes of possible moiré minibands at zero magnetic field [Phys. Rev. B 87, 245408 (2013); Phys. Rev. B 88, 205418; Phys. Rev. B 88, 155415 (2013)] and strong magnetic field [Nature 497, 594 (2013), arXiv:1310.8578] will be discussed. Experimentally available magnetic fields are enough to provide flux φ through the moiré superlattice cell comparable to the magnetic flux quantum φ0 and reach the regime of fractal Hofstadter spectra. As a result, a single device can offer a multiplicity of two-dimensional electron systems, realised at rational flux values  φ = φ0, φ0 /2, 2 φ0 /3, etc., each with its own intricate topological properties, including quantum Hall effect physics related to the effective Landau levels emerging from these magnetic minibands at the nearby range of magnetic fields.