Home
For authors
Submission status

Archive
Archive (English)
Current
   Volumes 113-119
   Volumes 93-112
      Volume 112
      Volume 111
      Volume 110
      Volume 109
      Volume 108
      Volume 107
      Volume 106
      Volume 105
      Volume 104
      Volume 103
      Volume 102
      Volume 101
      Volume 100
      Volume 99
      Volume 98
      Volume 97
      Volume 96
      Volume 95
      Volume 94
      Volume 93
Search
VOLUME 105 (2017) | ISSUE 8 | PAGE 477
Spin-controlled negative magnetoresistance resulting from exchange interactions
DOI: 10.7868/S0370274X17080021
Abstract
We studied conductivity of AlGaAs-GaAs quantum well structures (where centers of the wells were doped by Be) at temperatures higher than 4 K in magnetic fields up 10 T. Throughout all the temperature region considered the conductivity demonstrated activated behavior. At moderate magnetic fields 0.1 T<H<1 T we observed negative isotropic magnetoresistance which was linear in magnetic field while for magnetic field normal with respect to the plane of the wells the magnetoresistance was positive at H>2 T. To the best of our knowledge, it was the first observation of linear negative magnetoresistance which would be isotropic with respect to the direction of magnetic field. While the isotropic character of magnetoresistance apparently evidences role of spins, the existing theoretical considerations concerning spin effects in conductance fail to explain our experimental results. We believe that such a behavior can be attributed to spin effects supported by exchange interactions between localized states.