Nonequilibrium phenomena in two-dimensional electron Corbino rings at large filling factors

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Nonequilibrium phenomena in two-dimensional
electron Corbino rings at large filling
factors A.A. Bykov, I.S. Strygin, D.V. Dmitriev
Rzhanov Institute of Semiconductor Physics,
Siberian Branch, Russian Academy of Science,
630090 Novosibirsk, Russia S. Dietrich, S.A.
Vitkalov Physics Department, City College of the
City University of New York, New York 10031, USA

APPLIED PHYSICS LETTERS 100, 251602 (2012)
PHYSICAL REVIEW B 87, 081409(R) (2013)
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1. Hall-bar and Corbino-disk 2. 2D system
at large filling factors 3. Zener tunneling
between Landau orbits and Zero-differential
resistance in Hall bars 4. Samples and
experiment 5. Zener tunneling between Landau
orbits in two-dimensional electron Corbino
rings 6. Zero-differential conductance of
two-dimensional electrons in crossed electric and
magnetic fields 7. Summary
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Hall-bar
Corbino-disk
rxx (V23 /I14)(W/L) (V65 /I14)(W/L) rxy
V26 /I14 V35 /I14
sxx (I12/2pV12)ln(rout/rin)
rxx sxx /( sxx2 sxy2) rxy sxy /( sxx2
sxy2)
sxx rxx /( rxx2 rxy2) sxy rxy /(
rxx2 rxy2)
1/
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Quantum Hall Effect
K. v Klitzing, G. Dorda, M. Pepper. PRL 45, 494
(1980).
D. C. Tsui, H. L. Stormer, A. C. Gossard. PRL
48, 1559 (1982).
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2D systems at large filling factors
I. A. Dmitriev, A.D. Mirlin, D. G. Polyakov, M.
A. Zudov REV. MOD. PHYS. 84 (2012)
B gt 0
B gt 0
B 0

• ?/tq gt ?wc

g g0

• ltlt ?wc

• gt ?wc

e
e
g(e) g01-2lcos(2pe/?wc)
g0 m/p?2
l exp(-p/wctq)
fT
EF
fT 1/exp(e - EF )/kBT 1
E1
g (e)
g0
0
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Nonlinear magnetotransport in Hall bar
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Zener tunneling between Landau orbits
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Zener tunneling between Landau orbits in Hall bar
HIRO
2RceEH l?wc
DkF 2kF
C. L. Yang, J. Zhang, R. R. Du, J. A. Simmons, J.
L. Reno. PRL 89, 076801 (2002).
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Zero-Differential Resistance State of
Two-Dimensional Electron Systems in Strong
Magnetic Fields
A. A. Bykov, J-Q. Zhang, S, Vitkalov, A. Kalagin,
A. Bakarov, PRL 99, 116801 (2007).
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Heterostructure GaAs/AlAs
n 8?1015 ?-2 m 200 ?2/??
T 1.6 - 4.2 K B lt 2 T
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Magnetic field dependencies of the conductance
of "narrow" and "wide" 2D electronCorbino discs
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Zener tunneling between Landau orbits in Corbino
rings
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Zener tunneling between Landau orbits in Corbino
rings
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Zero-differential conductance of two-dimensional
electrons in crossed electric and magnetic fields
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Summary
Current induced oscillations of differential
conductivity of two-dimension electrons, placed
in quantizing magnetic fields, are observed in
GaAs quantum wells in Corbino geometry. The
oscillations are periodic in the square of the
inverse magnetic field and occur in Corbino rings
with a width which is much lesser than the radius
of the rings. The conductance oscillations are
described by Zener tunneling between Landau
orbits in the absence of the Hall electric field.
An electronic state with zero-differential
conductance is found in nonlinear response to an
electric field E applied to two dimensional
Corbino discs of highly mobile carriers placed in
quantizing magnetic fields. The state occurs
above a critical electric fieldE gt Eth at low
temperatures and is accompanied by an abrupt dip
in the differential conductance.
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