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Title: Experimental study of two-dimensional quantum Wigner solid in zero magnetic field

At temperatures T → 0, strongly interacting two-dimensional (2D) electron systems manifest characteristic insulating behaviors that are key for understanding the nature of the ground state in light of the interplay between disorder and electron-electron interaction. In contrast to the hopping conductance demonstrated in the insulating side of the metal-to-insulator transition, the ultra-high quality 2D systems exhibit nonactivated T-dependence of the conductivity even for dilute carrier concentrations down to 7×10{sup 8} cm{sup −2}. The apparent metal-to-insulator transition (MIT) occurs for a large r{sub s} value around 40 for which a Wigner Crystalllization is expected. The magnetoresistance for a series of carrier densities in the vicinity of the transition exhibits a characteristic sign change in weak perpendicular magnetic field. Within the Wigner Crystallization regime (with r{sub s} > 40), we report an experimental observation of a characteristic nonlinear threshold behavior from a high-resolution dc dynamical response as an evidence for aWigner crystallization in high-purity GaAs 2D hole systems in zero magnetic field. The system under an increasing current drive exhibits voltage oscillations with negative differential resistance. They confirm the coexistence of a moving crystal along with striped edge states as observed for electrons on helium surfaces. Moreover, the threshold is wellmore » below the typical classical levels due to a different pinning and depinning mechanism that is possibly related to quantum processes.« less
Authors:
 [1] ; ;  [2]
  1. Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201 (United States)
  2. Department of Electrical Engineering, Princeton University, Princeton, NJ 08544 (United States)
Publication Date:
OSTI Identifier:
22265944
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1590; Journal Issue: 1; Conference: International conference on electronic, photonic, plasmonic and magnetic properties of nanomaterials, London (Canada), 12-16 Aug 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CARRIER DENSITY; CRYSTALLIZATION; CRYSTALS; ELECTRIC POTENTIAL; ELECTRON-ELECTRON COLLISIONS; ELECTRON-ELECTRON COUPLING; ELECTRON-ELECTRON INTERACTIONS; ELECTRONS; GALLIUM ARSENIDES; GROUND STATES; HELIUM; MAGNETIC FIELDS; MAGNETORESISTANCE; OSCILLATIONS; SOLIDS; TWO-DIMENSIONAL CALCULATIONS