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

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. rings at large filling factors 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 rings at large filling factors

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/

3

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UIWSPS-2014 rings at large filling factors

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UIWSPS-2014 rings at large filling factors

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Quantum Hall Effect rings at large filling factors

K. vKlitzing, G. Dorda, M. Pepper.

PRL45, 494 (1980).

D. C. Tsui, H. L. Stormer, A. C. Gossard.

PRL48,1559 (1982).

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2D systems at large filling factors rings at large filling factors

I. A. Dmitriev, A.D. Mirlin, D. G. Polyakov, M. A. Zudov REV. MOD. PHYS. 84 (2012)

B > 0

B > 0

B = 0

- = /tq > wc

g = g0

- <<wc

- >wc

e

e

g(e) = g0[1-2lcos(2pe/wc)]

g0 = m*/p2

l = exp(-p/wctq)

fT

EF

fT = 1/{exp[(e- EF )/kBT] +1}

E1

g (e)

g0

0

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Zener tunneling between Landau orbits in Hall bar rings at large filling factors

“HIRO”

2RceEH = lwc

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 Electron Systems in Strong Magnetic Fields GaAs/AlAs

n ~ 81015 м-2

m ~ 200 м2/Вс

T = 1.6 - 4.2 K

B < 2 T

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UIWSPS-2014 Electron Systems in Strong Magnetic Fields

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Magnetic field dependencies of the conductance Electron Systems in Strong Magnetic Fields

of "narrow" and "wide" 2D electronCorbino discs

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Zener tunneling between Landau orbits in Corbino rings Electron Systems in Strong Magnetic Fields

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Zener tunneling between Landau orbits in Corbino rings Electron Systems in Strong Magnetic Fields

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Zero-differential conductance of two-dimensional electrons in crossed electric and magnetic fields

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UIWSPS-2014 in crossed electric and magnetic fields

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Summary in crossed electric and magnetic fields

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 > Eth at low temperatures and is accompanied by an abrupt dip in the differential conductance.

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