Imaging the zigzag Wigner crystal in confinement-tunable quantum wires

TL;DR

This paper reports the first direct imaging of zigzag Wigner crystals in tunable quantum wires, revealing their structural and spin phases, and highlighting potential applications in spintronics and quantum information.

Contribution

It provides experimental evidence of zigzag Wigner crystals in 1D quantum wires and maps their structural and spin phase diagrams.

Findings

Observation of zigzag Wigner crystals using charge and spin detectors

Mapping of structural and spin phase diagrams of 1D Wigner crystallization

Electrical control of spin phases in semiconductor systems

Abstract

The existence of Wigner crystallization, one of the most significant hallmarks of strong electron correlations, has to date only been definitively observed in two-dimensional systems. In one-dimensional (1D) quantum wires Wigner crystals correspond to regularly spaced electrons; however, weakening the confinement and allowing the electrons to relax in a second dimension is predicted to lead to the formation of a new ground state constituting a zigzag chain with nontrivial spin phases and properties. Here we report the observation of such zigzag Wigner crystals by use of on-chip charge and spin detectors employing electron focusing to image the charge density distribution and probe their spin properties. This experiment demonstrates both the structural and spin phase diagrams of the 1D Wigner crystallization. The existence of zigzag spin chains and phases which can be electrically controlled in semiconductor systems may open avenues for experimental studies of Wigner crystals and their technological applications in spintronics and quantum information.