Quantum melting of a two-dimensional Wigner crystal
Institute of Solid-State Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region, Russian Federation
The paper reviews theoretical predictions for the behavior of two-dimensional low-density electron systems at near absolute zero temperatures, including the formation of an electron (Wigner) crystal, crystal melting at a critical electron density, and transitions between crystal modifications in more complex (for example, two-layer) systems. The paper presents experimental results obtained from real two-dimensional systems in which the non-conducting (solid) state of the electronic system with indications of collective localization is actually realized. Experimental methods for detecting a quantum liquid-solid phase interface are discussed.