Spin filtering effect generated by the inter-subband spin-orbit coupling in the bilayer nanowire with the quantum point contact

Abstract

The spin filtering effect in the bilayer nanowire with quantum point contact is investigated theoretically. We demonstrate the new mechanism of the spin filtering based on the lateral inter-subband spin-orbit coupling, which for the bilayer nanowires has been reported to be strong. The proposed spin filtering effect is explained as the joint effect of the Landau-Zener intersubband transitions caused by the hybridization of states with opposite spin (due to the lateral Rashba SO interaction) and the confinement of carriers in the quantum point contact region.

Tuning Rashba spin-orbit coupling in homogeneous semiconductor nanowires

“…Such intersubband SOC has been related to intriguing physical phenomena, such as unusual Zitterbewegung, 48 intrinsic spin Hall effect in symmetric quantum well 49 and spin filtering devices. 50,51 Below we analyze inter-subband SOC between the ground state and the two lowest excited states. Figure 7 shows |α 12 x(y) | and |α 13 x(y) | as a function of the gate voltage V g in the low electron concentration regime, n e = 10 7 cm −3 .…”

“…Such intersubband SOC has been related to intriguing physical phenomena, such as unusual Zitterbewegung, 48 intrinsic spin Hall effect in symmetric quantum well 49 and spin filtering devices. 50,51 Below we analyze inter-subband SOC between the ground state and the two lowest excited states.…”

Enhanced Rashba spin-orbit coupling in core-shell nanowires by the interfacial effect

“…Among other parameters, qubit protection at sufficiently high temperatures relies on a large SOC which determines the topological gap. Additionally, electrical control of SOC is necessary in the realization of spintronic devices [16][17][18][19][20][21][22][23][24][25][26] .…”

Helical and topological phase detection based on nonlocal conductance measurements in a three terminal junction

“…Spin-orbit (SO) interaction, which couples the spin of electrons to their momentum, is an essential ingredient of many quantum devices including spin qubits 1,2 , spintronic devices [3][4][5][6][7][8] , Cooper pair splitters 9,10 or Majorana nanowires [11][12][13] . In general, this relativistic phenomenon results from breaking the inversion symmetry which, in semiconductors, could be either intrinsic, related to the crystallographic structure (Dresselhaus SO coupling 14 ), or may be induced by the confinement potential (Rashba SO coupling 15,16 ) in an electrically controllable fashion.…”

“…The ability to control the Rashba SO component makes it especially important in spintronics applications and Majorana zero mode (MZM) engineering where the spin can be altered electrically via external gates attached to the nanostructure. 5,6,17,18 For this reason, zincblende nanowires (NWs) grown along the [111] direction, which preserves the crystal inversion symmetry and makes the Dresselhaus term negligible 19 , have attracted the growing interest in recent years 17,[19][20][21][22][23][24] .…”