Abstract
Band-inverted electron-hole bilayers support quantum spin Hall insulator and exciton condensate phases. Interest in quantum spin Hall effect in these systems has recently put them in the spotlight. We investigate such a bilayer in an external magnetic field. We show that the interlayer correlations lead to formation of a helical quantum Hall exciton condensate state. Existence of the counterpropagating edge modes in this system results in formation of a ground state spin-texture not supporting gapless single-particle excitations. The charged edge excitations in a sufficiently narrow Hall bar are confined: a charge on one of the edges always gives rise to an opposite charge on the other edge. Magnetic field and gate voltages allow the control of a confinement-deconfinement transition of charged edge excitations, which can be probed with nonlocal conductance. Confinement-deconfinement transitions are of great interest, not least because of their possible significance in shedding light on the confinement problem of quarks.
| Original language | English |
|---|---|
| Article number | 10462 |
| Journal | Nature Communications |
| Volume | 7 |
| DOIs | |
| Publication status | Published - 25 Jan 2016 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work was supported by the Academy of Finland Center of Excellence program, the European Research Council (Grant No. 240362-Heattronics), the Dutch Science Foundation NWO/FOM, NSERC, CIfAR, Max Planck\u2014UBC Centre for Quantum Materials, and the DFG grant RE 2978/1-1.
