Majorana zero modes from topological kink states in the two-dimensional electron gas

Abstract

Majorana zero modes (MZMs)-bearing potential applications for topological quantum computingare verified in quasi-one-dimensional (1D) Fermion systems, including semiconductor nanowires, magnetic atomic chains, planar Josephson junctions. However, the existence of multi-bands in these systems makes the MZMs fragile to the influence of disorder. Moreover, in practical perspective, the proximity induced superconductivity may be difficult and restricted for 1D systems. Here, we propose a flexible route to realize MZMs through 1D topological kink states by engineering a 2D electron gas with antidot lattices, in which both the aforementioned issues can be avoided owing to the robustness of kink states and the intrinsically attainable superconductivity in high-dimensional systems. The MZMs are verified to be quite robust against disorders and the bending of kink states, and can be conveniently tuned by varying the Rashba spin-orbit coupling strength. Our proposal provides an experimental feasible platform for MZMs with systematic manipulability and assembleability based on the present techniques in 2D electron gas system.

Topological phase transitions and Majorana zero modes induced by the periodic potential in an antiferromagnetic chain

“…To verify the existence of MZM in a 1D AFM chain in more detail, we employ the nonequilibrium Green's function method [65] to investigate the transport properties through the 1D AFM chain connected by two normal-metal electrodes. There are three kinds of transport processes in this twoelectrode device, such as quantum tunneling, the Andreev reflection, and crossed Andreev reflection.…”

The realization of quantum anomalous Hall effect in two dimensional electron gas

“…We first start from a 2DEG with exchange field and RSOC and the Hamiltonian is given as follows [37][38][39]:…”

“…α R is defined by α R = α/2a 0 . Now we construct an artificial graphene in 2DEG by introducing the anti-dot lattice [39]. As shown in figure 1(a), the rectangular-shaped supercell is displayed, whose size is a × √ 3a.…”

“…Till now, we have determined the existence of QAHE phases in our system. Very recently, some progress has been made in theory [26][27][28]39] and experiments [29,30] in the artificial graphene-like systems. The graphene band can be tuned by varying the size, the shape, and the orientation of anti-dots in 2DEG.…”

Topological kink states in graphene

“…Here, both the magnetic field and the gate voltage can be utilized to manipulate the kink states. Besides, not long ago, due to the one-dimensional (1D) nature of the topological kink states, the robustness of the Majorana zero modes (MZMs) at the ends of topological kink states was also demonstrated [68].…”