TY - JOUR

T1 - Quantum electron transport in magnetically entangled subbands

AU - Mayer, William

AU - Vitkalov, Sergey

AU - Bykov, A. A.

PY - 2017/7/28

Y1 - 2017/7/28

N2 - Transport properties of highly mobile two-dimensional (2D) electrons in symmetric GaAs quantum wells with two populated subbands placed in tilted magnetic fields are studied at high temperatures. Quantum positive magnetoresistance (QPMR) and magneto-intersubband resistance oscillations (MISO) are observed in quantizing magnetic fields, B¥, applied perpendicular to the 2D layer. QPMR displays contributions from electrons with considerably different quantum lifetimes, τq(1,2), confirming the presence of two subbands in the studied system. MISO evolution with B¥ agrees with the obtained quantum scattering times only if an additional reduction of the MISO magnitude is applied at small magnetic fields. This indicates the presence of a yet unknown mechanism leading to MISO damping. Application of an in-plane magnetic field produces a strong decrease of both QPMR and MISO magnitude. The reduction of QPMR is explained by spin splitting of Landau levels indicating a g factor, g≈0.4, which is considerably less than the g factor found in GaAs quantum well with a single subband populated. In contrast to QPMR, the decrease of MISO magnitude is largely related to the in-plane magnetic field induced entanglement between quantum levels in different subbands that, in addition, increases the MISO period.

AB - Transport properties of highly mobile two-dimensional (2D) electrons in symmetric GaAs quantum wells with two populated subbands placed in tilted magnetic fields are studied at high temperatures. Quantum positive magnetoresistance (QPMR) and magneto-intersubband resistance oscillations (MISO) are observed in quantizing magnetic fields, B¥, applied perpendicular to the 2D layer. QPMR displays contributions from electrons with considerably different quantum lifetimes, τq(1,2), confirming the presence of two subbands in the studied system. MISO evolution with B¥ agrees with the obtained quantum scattering times only if an additional reduction of the MISO magnitude is applied at small magnetic fields. This indicates the presence of a yet unknown mechanism leading to MISO damping. Application of an in-plane magnetic field produces a strong decrease of both QPMR and MISO magnitude. The reduction of QPMR is explained by spin splitting of Landau levels indicating a g factor, g≈0.4, which is considerably less than the g factor found in GaAs quantum well with a single subband populated. In contrast to QPMR, the decrease of MISO magnitude is largely related to the in-plane magnetic field induced entanglement between quantum levels in different subbands that, in addition, increases the MISO period.

KW - 2-DIMENSIONAL SYSTEMS

KW - FERMI-SURFACE

KW - BREAKDOWN

KW - FIELD

KW - HETEROSTRUCTURES

KW - SCATTERING

KW - WELL

KW - GAS

UR - http://www.scopus.com/inward/record.url?scp=85027274434&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.96.045436

DO - 10.1103/PhysRevB.96.045436

M3 - Article

AN - SCOPUS:85027274434

VL - 96

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 4

M1 - 045436

ER -