Confinement-deconfinement transition due to spontaneous symmetry breaking in quantum Hall bilayers
Pikulin, D. I., Silvestrov, P. G., & Hyart, T. (2016). Confinement-deconfinement transition due to spontaneous symmetry breaking in quantum Hall bilayers. Nature Communications, 7, 10462. doi:10.1038/ncomms10462
Published inNature Communications
© 2016 the Authors. Published by Nature Publishing Group. This is an open access article licensed under a Creative Commons Attribution 4.0 International License.
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. ...