EVIDENCE FOR A LIQUID-TO-CRYSTAL PHASE-TRANSITION IN A CLASSICAL, 2-DIMENSIONAL SHEET OF ELECTRONS

Experimental evidence is presented for an electron-liquid to electron-crystal phase transition in a sheet of electrons on a liquid-He surface. The phase transition has been studied for electron areal densities from 3×108 cm-2 to 9×108 cm-2 and has yielded melting temperatures between 0.35 and 0.65 K. The phase transition occurs at =137 15, where is a measure of the ratio of potential energy to kinetic energy per electron. © 1979 The American Physical Society.