Robin Nicholas

Abstract:

We describe the properties of the strongly interacting 2-D electron gas in high magnetic fields whose properties can be described in terms of the formation of composite fermions at fractional Landau level occupancy. For a Landau level occupancy v = 1 the excitations correspond to spin waves for high g-factors and magnetic fields, but when the g-factor is reduced close to zero by the use of hydrostatic pressure, there is strong evidence for the formation of Skyrmions. Studies of the composite fermions in the limit of vanishing Zeeman energy also suggest that skyrmionic excitations can occur for composite fermions. (C) 1998 Elsevier Science B.V. All rights reserved.

Abstract:

The combination of a 60 T pulsed-field magnet and the continuous tunability of a high power, picosecond free-electron laser provides a powerful facility to study, e.g. cyclotron resonance in a wide range of materials with different effective masses and over a wide range of energies. Here we present the first cyclotron resonance data obtained with this new and unique combination of far-infrared radiation and high magnetic fields. (C) 1998 Elsevier Science B.V. All rights reserved.