arXiv subjects

K. W. Baldwin

Publications and source records attributed to K. W. Baldwin.

165 records · Page 10Linked to original sources

arXiv1999

Strongly Anisotropic Electronic Transport at Landau Level Filling Factor $ν= 9/2$ and $ν= 5/2$ Under Tilted Magnetic Field

We have investigated the influence of an increasing in-plane magnetic field on the states at half-filling of Landau levels ($ν$ = 11/2, 9/2, 7/2, and 5/2) of a two-dimensional electron system. In the electrically anisotropic phase at $ν$ = 9/2 and 11/2 an in-plane magnetic field of $\sim$ 1-2 T overcomes its initial pinning to the crystal lattice and {\it reorient} this phase. In the initially isotropic phases at $ν$ = 5/2 and 7/2 an in-plane magnetic field {\it induces} a strong electrical anisotropy. In all cases, for high in-plane fields, the high resistance axis is parallel to the direction of the in-plane field.

cond-mat.mes-hall↗

arXiv1998

Strongly Anisotropic Transport in Higher Two-Dimensional Landau Levels

Low-temperature, electronic transport in Landau levels N>1 of a two-dimensional electron system is strongly anisotropic. At half-filling of either spin level of each such Landau level the magnetoresistance either collapses to form a deep minimum or is peaked in a sharp maximum, depending on the in-plane current direction. Such anisotropies are absent in the N=0 and N=1 Landau level, which are dominated by the states of the fractional quantum Hall effect. The transport anisotropies may be indicative of a new many particle state, which forms exclusively in higher Landau levels.

cond-mat.mes-hall↗

arXiv1998

Effective Mass and g-Factor of Four Flux Quanta Composite Fermions

We investigate the properties of composite fermions with four attached flux quanta through tilted field experiments near Landau level filling factor nu = 3/4. The observed collapse of fractional quantum Hall gaps in the vicinity of this quarter-filling state can be comprehensively understood in terms of composite fermions with mass and spin. Remarkably, the effective mass and g-factor of these four flux quanta composite fermions around nu = 3/4 are very similar to those of two flux quanta composite fermions around nu = 3/2.

cond-mat.mes-hall↗