Longitudinal autosoliton motion across p -InSb in a transverse magnetic field
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TRONIC AND OPTICAL PROPERTIES OF SEMICONDUCTORS
Longitudinal Autosoliton Motion Across p-InSb in a Transverse Magnetic Field I. K. Kamilov, A. A. Stepurenko, A. E. Gummetov, and A. S. Kovalev^ Institute of Physics, Dagestan Scientific Center, Russian Academy of Sciences, ul. 26 Bakinskikh komissarov 94, Makhachkala, 367003 Russia ^e-mail: [email protected] Submitted August 24, 2006; accepted for publication September 4, 2006
Abstract—It is experimentally shown that a longitudinal autosoliton excited by an electric field in nonequilibrium electron–hole plasma in p-InSb moves towards the sample periphery under the effect of a transverse magnetic field. This sample region is characterized by a lowered temperature and by the fact that the unstable existence of the autosoliton leads to a cyclic process causing current oscillations in the sample circuit. An average velocity of the autosoliton motion amounts to 2 × 102–3 × 103 cm/s in a magnetic field within the range of 5962.5–22657.5 A/m. PACS numbers: 42.65.Tg, 52.35.Sb DOI: 10.1134/S1063782607030062
In [1], Zvezdin and Osipov considered the electrical properties of semiconductors in which a negative resistance is formed due to a heavy temperature dependence of the conductivity in crossed magnetic and electric fields. It was shown that, for a certain sample configuration, a solitary current-density wave moving with a constant velocity in a direction perpendicular to the electric and magnetic fields is formed; the velocity of the current-pinch motion was estimated. In [2, 3], it was shown that a dissipative structure arises in a nonequilibrium excited electron–hole plasma (EHP) created by Joule heating of p-InSb. This structure represents the EHP with localized areas of extreme charge-carrier concentration and temperature—autosolitons (ASs) both in the form of current layers (longitudinal ASs) and strong-electric-field layers (transverse ASs). It was established in [4] that the longitudinal ASs in p-InSb are realized as localized regions with an increased charge-carrier concentration and lowered temperature; i.e., these regions are cold. It was experimentally observed in [5] that longitudinal ASs are divided under the effect of a longitudinal magnetic field. In an electric field, the longitudinal cold AS in p-InSb represents a current pinch with the corresponding current-density distribution over the pinch cross section [4, 6]. By applying a transverse magnetic field, it is apparently possible, as was shown in [1], to set in motion a longitudinal autosoliton (AS) in the sample in the direction perpendicular to electric and magnetic fields without following special restrictions imposed on the shape and sizes of the samples.
The aim of this study was to observe and investigate the phenomenon of longitudinal-autosoliton motion in the case where a sample is under the effect of a magnetic field transverse to the direction of the current flow through the sample. The measurements were carried out at T = 77 K for the samples with the carrier concentration p = 1.9 × 1012 cm–3 and the
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