arXiv subjects

M. P. Sarachik

Publications and source records attributed to M. P. Sarachik.

61 records · Page 4Linked to original sources

arXiv1998

H/T Scaling of the Magnetoconductance in Two Dimensions near the Conductor-Insulator Transition

For an electron density near the H=0 insulator-to-conductor transition, the magnetoconductivity of the low-temperature conducting phase in high-mobility silicon MOSFETs is consistent with the form $Δσ(H_{||},T)\equivσ(H_{||},T)-σ(0,T) = f(H_{||}/T)$ for magnetic fields $H_{||}$ applied parallel to the plane of the electron system. This sets a valuable constraint on theory and provides further evidence that the electron spin is central to the anomalous H=0 conducting phase in two dimensions.

cond-mat.dis-nn↗

arXiv1997

Effect of Tilted Magnetic Field on the Anomalous H=0 Conducting Phase in High-Mobility Si MOSFETs

The suppression by a magnetic field of the anomalous H=0 conducting phase in high-mobility silicon MOSFETs is independent of the angle between the field and the plane of the 2D electron system. In the presence of a parallel field large enough to fully quench the anomalous conducting phase, the behavior is similar to that of disordered GaAs/AlGaAs heterostructures: the system is insulating in zero (perpendicular) field and exhibits reentrant insulator-quantum Hall effect-insulator transitions as a function of perpendicular field. The results demonstrate that the suppression of the low-T phase is related only to the electrons' spin.

cond-mat.str-el↗

arXiv1997

Reply to the Comment on "Electric Field Scaling at a B=0 Metal-Insulator Transition in Two Dimensions"

We note that data on Si/SiGe heterostructures, reported in the Comment of Ismail et al. (cond-mat/9707061) on our recent Letter (cond-mat/9608101), are insufficient to establish the claim for a transition to a metallic phase.

cond-mat.str-el↗

arXiv1997

The metal-insulator transition in Si:X: Anomalous response to a magnetic field

The zero-temperature magnetoconductivity of just-metallic Si:P scales with magnetic field, H, and dopant concentration, n, lying on a single universal curve. We note that Si:P, Si:B, and Si:As all have unusually large magnetic field crossover exponents near 2, and suggest that this anomalously weak response to a magnetic field is a common feature of uncompensated doped semiconductors.

cond-mat.str-el↗

arXiv1997

Magnetic Field Suppression of the Conducting Phase in Two Dimensions

The anomalous conducting phase that has been shown to exist in zero field in dilute two-dimensional electron systems in silicon MOSFETs is driven into a strongly insulating state by a magnetic field of about 20 kOe applied parallel to the plane. The data suggest that in the limit of T -> 0 the conducting phase is suppressed by an arbitrarily weak magnetic field. We call attention to striking similarities to magnetic field-induced superconductor-insulator transitions.

cond-mat.str-el↗

arXiv1996

Reflection symmetry at a B=0 metal-insulator transition in two dimensions

We report a remarkable symmetry between the resistivity and conductivity on opposite sides of the B=0 metal-insulator transition in a two-dimensional electron gas in high-mobility silicon MOSFET's. This symmetry implies that the transport mechanisms on the two sides are related.

cond-mat.mes-hall↗

arXiv1996

Electric field scaling at a B=0 metal-insulator transition in two dimensions

The non-linear (electric field-dependent) resistivity of the 2D electron system in silicon exhibits scaling as a function of electric field and electron density in both the metallic and insulating phases, providing further evidence for a true metal-insulator transition in this 2D system at B=0. Comparison with the temperature scaling yields separate determinations of the correlation length exponent, ν=1.5, and the dynamical exponent, z=0.8, close to the theoretical value z=1.

cond-mat↗