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Selected Works

2008

Carrier density

Articles 1 - 2 of 2

Full-Text Articles in Physics

Spin-Orbit Coupling In An In0.52Ga0.48As Quantum Well With Two Populated Subbands, P. J. Simmonds, S. N. Holmes, H. E. Beere, D. A. Ritchie Jun 2008

Spin-Orbit Coupling In An In0.52Ga0.48As Quantum Well With Two Populated Subbands, P. J. Simmonds, S. N. Holmes, H. E. Beere, D. A. Ritchie

Paul J. Simmonds

Structural inversion asymmetry controls the magnitude of Rashba spin-orbit coupling in the electron energy spectrum of a narrow band gap semiconductor. We investigate this effect for a series of two-dimensional electron gases in In0.52Ga0.48As quantum wells, surrounded by In0.52Al0.48As barriers, where either one or two electric subbands are populated. Structural inversion asymmetry does not exist at low carrier density while at higher carrier densities (above (4–5) × 1011 cm−2), a finite spin splitting is observed. The spin orbit coupling coefficients (α) are determined from the power spectrum …


Quantum Transport In In0.75Ga0.25As Quantum Wires, P. J. Simmonds, F. Sfigakis, H. E. Beere, D. A. Ritchie, M. Pepper, D. Anderson, G. A.C. Jones Apr 2008

Quantum Transport In In0.75Ga0.25As Quantum Wires, P. J. Simmonds, F. Sfigakis, H. E. Beere, D. A. Ritchie, M. Pepper, D. Anderson, G. A.C. Jones

Paul J. Simmonds

In addition to quantized conductance plateaus at integer multiples of 2e2/h, the differential conductance G=dI/dV shows plateaus at 0.25(2e2/h) and 0.75(2e2/h) under applied source-drain bias in In0.75Ga0.25As quantum wires defined by insulated split gates. This observation is consistent with a spin-gap model for the 0.7 structure. Using a tilted magnetic field to induce Landau level crossings, the g factor was measured to be ~9 by the coincidence method. This material, with a mobility of 1.8×105 cm …