Vortex lattice states of bilayer electron-hole fluids in quantizing magnetic fields

TL;DR

This paper predicts that in a strong magnetic field, a bilayer electron-hole fluid forms a vortex lattice with unique properties, and increasing density or reducing field causes a transition detectable via transport measurements.

Contribution

It introduces a novel vortex lattice state with fractional charges and a honeycomb structure in electron-hole fluids under magnetic fields.

Findings

Vortex lattice with fractional charges and honeycomb structure identified.

Transition to delocalized vortices predicted with increased density or decreased magnetic field.

Experimental signature includes a sharp rise in counterflow transport resistance.

Abstract

We show that the ground state of a weakly charged two-dimensional electron-hole fluid in a strong magnetic field is a broken translation symmetry state with interpenetrating lattices of localized vortices and antivortices in the electron-hole-pair field. The vortices and antivortices carry fractional charges of equal sign but unequal magnitude and have a honeycomb lattice structure that contrasts with the triangular lattices of superconducting electron-electron-pair vortex lattices. We predict that increasing charge density or weakening magnetic field drives a vortex delocalization transition that would be signaled experimentally by an abrupt increase in counterflow transport resistance.