Non-linear miniband conduction in crossed electric and magnetic fields

Palmier, J.F.; Sibille, Alain; Etemadi, G.; Celeste, A.; Portal, J. C.

doi:10.1088/0268-1242/7/3b/069

Cited by 16 publications

(6 citation statements)

References 6 publications

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“…Within the semiclassical theory the temporal evolution of the distribution function is given by the Boltzmann equation 5 ∂f (q, k, ν, t) ∂t + eF ∂f ∂q = ∂f ∂t scatt (35) which is derived in most textbooks on solid state physics. (The inclusion of magnetic fields is straightforward and results for superlattice structures are given in [84,85]; see also [86] for corresponding experimental results. Recently, a mechanism for spontaneous current generation due to the presence of hot electron in a magnetic field perpendicular to the superlattice direction was proposed [87].)…”

Section: Miniband Transportmentioning

confidence: 99%

Semiconductor superlattices: a model system for nonlinear transport

2002

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Electric transport in semiconductor superlattices is dominated by pronounced negative differential conductivity. In this report the standard transport theories for superlattices, i.e. miniband conduction, Wannier-Stark-hopping, and sequential tunneling, are reviewed in detail. Their relation to each other is clarified by a comparison with a quantum transport model based on nonequilibrium Green functions. It is demonstrated how the occurrence of negative differential conductivity causes inhomogeneous electric field distributions, yielding either a characteristic sawtooth shape of the current-voltage characteristic or self-sustained current oscillations. An additional ac-voltage in the THz range is included in the theory as well. The results display absolute negative conductance, photon-assisted tunneling, the possibility of gain, and a negative tunneling capacitance. 2 Notation and list of symbolsThroughout this work we consider a superlattice, which is grown in the z direction. Vectors within the (x, y) plane parallel to the interfaces are denoted by bold face letters k, r, while vectors in 3 dimensional space are r, k, . . . . All sums and integrals extend from −∞ to ∞ if not stated otherwise.The following relations are frequently used in this work and are given here for easy reference:

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Section: Miniband Transportmentioning

confidence: 99%

Semiconductor superlattices: a model system for nonlinear transport

2002

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“…Moreover, the minimum, observed at large angles and low magnetic fields in the second derivative of G, comes from the maximum of the magnetoconductance occurring in the crossed-fields configuration when the applied electric field is located in the nonlinear regime of the current-voltage characteristic. This effect, induced by a magnetic field applied parallel to the layers of a superlattice and due to the presence of a point of inflection in the dispersion along the growth axis, has been described theoretically using a semiclassical approach 24,25 and also observed experimentally. 26,27 Oscillations start to appear around 45°, but at higher magnetic field than for the magnetic field along the growth axis.…”

Section: A Miniband Dependencementioning

confidence: 97%

Magnetophonons in short-period superlattices

et al. 1996

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We report the observation of magnetophonon resonances on the background of the longitudinal magnetoconductance in short-period GaAs/AlAs semiconductor superlattices. Both the GaAs and the AlAs longitudinal optical phonons are observed. We show how the enhancement of the magnetophonon effect with electric field is connected to the shift of the electron distribution towards the high-velocity and low-density-of-states region at the midpoint of the reduced Brillouin zone. The observed temperature dependence can be explained by considering the competition between the phonon population and the electron lifetime. The two superposed series of the GaAs and the AlAs optical phonons are shifted when hydrostatic pressure is applied and the relative strength of each series changes as the ⌫ miniband comes closer to the X states.

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“…But when elastic scattering cannot be neglected, the problem of drift in the presence of a magnetic field becomes much more complicated. Palmier et al 11 , Miller and Laikhtman 13 , and Cannon et al 14 , applied different approaches to the problem for the case when the magnetic field is perpendicular to the SL axis. Resonant drift enhancement is then irrelevant.…”

Section: Presentation Of the Drift In The Form Similar To That Inmentioning

confidence: 99%

“…Our present research falls into one of its sub-areas, studying how magnetic field affects electron transport in SLs. Most works in this subarea considered cases when the magnetic field was either perpendicular to the SL axis [8][9][10][11][12][13][14][15] or, more rarely, parallel to it 10,16 . It would be natural to expect that an intermediate tilt would give rise either to a mixture of phenomena characteristic of the perpendicular and parallel orientations, or to a less pronounced manifestation of one of them, rather than to distinctly new phenomena.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of resonant enhancement of electron drift in nanometer semiconductor superlattices subjected to electric and inclined magnetic fields

Soskin¹,

Khovanov²,

McClintock³

2019

Phys. Rev. B

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We address the increase of electron drift velocity that arises in semiconductor superlattices (SLs) subjected to constant electric and magnetic fields. It occurs if the magnetic field possesses nonzero components both along and perpendicular to the SL axis and the Bloch oscillations along the SL axis become resonant with cyclotron rotation in the transverse plane. It is a phenomenon of considerable interest, so that it is important to understand the underlying mechanism. In an earlier Letter (Phys. Rev. Lett. 114, 166802 (2015)) we showed that, contrary to a general belief that drift enhancement occurs through chaotic diffusion along a stochastic web (SW) within semiclassical collisionless dynamics, the phenomenon actually arises through a non-chaotic mechanism. In fact, any chaos that occurs tends to reduce the drift. We now provide fuller details, elucidating the mechanism in physical terms, and extending the investigation. In particular, we: (i) demonstrate that pronounced drift enhancement can still occur even in the complete absence of an SW; (ii) show that, where an SW does exist and its characteristic slow dynamics comes into play, it suppresses the drift enhancement even before strong chaos is manifested; (iii) generalize our theory for non-small temperature, showing that heating does not affect the enhancement mechanism and accounting for some earlier numerical observations; (iv) demonstrate that certain analytic results reported previously are incorrect; (v) provide an extended critical review of the subject and closely related issues; and (vi) discuss some challenging problems for the future.

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Non-linear miniband conduction in crossed electric and magnetic fields

Cited by 16 publications

References 6 publications

Semiconductor superlattices: a model system for nonlinear transport

Semiconductor superlattices: a model system for nonlinear transport

Magnetophonons in short-period superlattices

Mechanism of resonant enhancement of electron drift in nanometer semiconductor superlattices subjected to electric and inclined magnetic fields

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