A299

Surface Science 98 (1980) 256-261 0 North-Holland Publishing Company and Yamada Science Foundation

SUBMILLIMETER LASER CYCLOTRON RESONANCE OF INVERSION

LAYERS AT LOW ELECTRON DENSITIES

RJ. WAGNER

Naval Research Laboratory, Washington, DC 20375, USA

and D.C. TSUI

Bell Laboratories, Murray Hill. New Jersey 079 74, USA

Received 20 July 1979

Submillimeter laser cyclotron resonance experiments on low density electron inversion layers in ( 1OO)Si MOSFETs have shown an anomalously narrow line under certain conditions of temperature, time, electron density and magnetic field. If the lowest Landau level is less than half-filled, the line position is independent of density. In this regime, the line position shows behavior qualitatively similar to that of weakly-bound carriers in bulk semiconductors.

Surface Science 98 (1980) 262-271 0 North-Holland Publishing Company and Yamada Science Foundation

EVIDENCE FOR A COLLECTIVE GROUND STATE IN Si INVERSION LAYERS

IN THE EXTREME QUANTUM LIMIT

B.A. WILSON, S.J. ALLEN, Jr. and D.C. TSUI Bell Laboratories, Murray Hill, New Jersey 07974, USA

Received 17 July 1979

IR measurements of the cyclotron resonance in the two-dimensional electron gas reveal a remarkable line narrowing and shift if and only if the lowest Landau level is partially occupied. This behavior cannot be explained in terms of single electron models, and strongly suggests a highly correlated or crystallized ground state, whose properties are compared with existing theories.

Surface Science 98 (1980) 272-275 0 North-Holland Publishing Company and Yamada Science Foundation

CHARGE DENSITY WAVE STATE OF TWO-DIMENSIONAL ELECTRONS

IN STRONG MAGNETIC FIELDS Daijiro YOSHIOKA and Hidetoshi FUKUYAMA The Institute for Solid State Physics, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106, Japan

Received 20 July 1979

The charge-density-wave (CDW) state at the quantum limit is investigated at absolute zero within the framework of the Hartree-Fock approximation. As a function of the fractional