Valley-polarized tunneling currents in bilayer graphene tunneling transistors

Abstract

We study theoretically the electron current across a monolayer graphene/hexagonal boron nitride/bilayer graphene tunnelling junction in an external magnetic field perpendicular to the layers. We show that change in effective tunnelling barrier width for electrons on different graphene layers of bilayer graphene, coupled with the fact that its Landau level wave functions are not equally distributed amongst the layers with a distribution that is reversed between the two valleys, lead to valley polarisation of the tunnelling current. We estimate that valley polarisation ∼ 70% can be achieved in high quality devices at B = 1 T. Moreover, we demonstrate that strong valley polarisation can be obtained both in the limit of strong-momentum conserving tunnelling and in lower quality devices where this constraint is lifted. * J.J.P. Thompson@bath.ac.uk FIG. 1. (Color online) Schematic of the tunnelling device discussed here. Also shown are the tuning potentials V b , Vg and Vt and direction of the applied magnetic field B.arXiv:1811.04687v2 [cond-mat.mes-hall]

Theoretical valley-polarized subgap transport and intravalley pairing states in a silicene-based antiferromagnet–superconductor junction

“…Similar to spintronics, a main challenge in valleytronics is how to effectively control and manipulate the valley degree of freedom [24][25][26]. The valley-dependent transport and applications have been extensively studied, including the valley Hall [27] or anomalous Hall effect [28], valley-dependent AR [29] or crossed AR (CAR) [30], valley caloritronics [31], valley filter effect [32], and valley transistors [33]. For instances, Gao et al have studied the retro-AR and specular AR in the proximitized graphene/SC junction and revealed that occurrences of two ARs are determined by the spin-valley indices [29].…”

Gap states and valley-spin filtering in transition metal dichalcogenide monolayers

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Valley-exchange coupling probed by angle-resolved photoluminescence

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