Weak antilocalization in quantum wells in tilted magnetic fields

Abstract

Weak antilocalization is studied in an InGaAs quantum well. Anomalous magnetoresistance is measured and described theoretically in fields perpendicular, tilted and parallel to the quantum well plane. Spin and phase relaxation times are found as functions of temperature and parallel field. It is demonstrated that spin dephasing is due to the Dresselhaus spin-orbit interaction. The values of electron spin splittings and spin relaxation times are found in the wide range of 2D density. Application of in-plane field is shown to destroy weak antilocalization due to competition of Zeeman and microroughness effects. Their relative contributions are separated, and the values of the in-plane electron g-factor and characteristic size of interface imperfections are found.Comment: 8 pages, 8 figure

One-particle conductance of an open quasi-two-dimensional Fermi system: Evidence of the parallel-magnetic-field-induced mode reduction effect

“…When decreasing the mean free path, non-monotonicity becomes so apparent that it appears to be inadmissible to disregard this effect in the experimental data. In particular, with regard to this analysis it would be tempting to revise the observed positive magnetoresistance which is frequently attributed to spin properties of 2D systems [42,43].…”

Weak field magnetoresistance of narrow-gap semiconductor InSb

“…In the second category the magnetoresistance curves in tilted magnetic field don't collapse into those in perpendicular field. This non-trivial anisotropy has been identified and systematically studied in quantum well systems, [4][5][6][7] MOSFET 8 and a few films. [9][10][11] Two mechanisms have been proposed as possible explanations for this anisotropy.…”

“…[9][10][11] Two mechanisms have been proposed as possible explanations for this anisotropy. One is the random Berry phase induced by in-plane field-the roughness effect; 4,8 the other is a mixing of singlet and triplet Cooperon due to Zeeman coupling-the Zeeman mechanism. [4][5][6][7] There have been quite few researches concerning the anisotropy of magnetoresistance in thin films and the mostly anisotropy investigated is in pure weak localization effect.…”

“…One is the random Berry phase induced by in-plane field-the roughness effect; 4,8 the other is a mixing of singlet and triplet Cooperon due to Zeeman coupling-the Zeeman mechanism. [4][5][6][7] There have been quite few researches concerning the anisotropy of magnetoresistance in thin films and the mostly anisotropy investigated is in pure weak localization effect. Some found that weak localization effect in perpendicular field is different from that in parallel field and in-plane field can even change the sign of weak field magnetoresistance.…”

“…Our results show that the anisotropy investigated in our InSb sample is different from that discovered in some quantum wells and films, in which the Zeeman effect has a strong influence on anisotropy of weak field magnetoresistance. [4][5][6][7][9][10][11] …”