Spin Gunn Effect

Yang, Qi; Yu, Zhi-Gang; Flatté, Michael E.

doi:10.1103/physrevlett.96.026602

Cited by 33 publications

(36 citation statements)

References 22 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This conclusion is at variance with the hypothesis of the previous work [14] and is based on recent measurements of the dependence of the scattering time on kinetic energy [40], as defined by the value of p in Eq. (16). The value of p is found to be strongly reduced from 3/2 due to scattering with charged impurities, as a consequence of the screening by holes.…”

Section: Discussionmentioning

confidence: 94%

“…Recently a new spin-charge coupling phenomenon resulting from Pauli blockade in a degenerate electron gas was revealed [14], resulting in a spin-dependence of the diffusion constant as large as 50%. Pauli blockade had been implicitely included in some theoretical treatments of spin polarized electron transport [13,15,16], but had not yet been explicitely detailed nor experimentally demonstrated. It is of importance since it will naturally modify all other coupling phenomena in the degenerate limit.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of the Pauli principle on photoelectron spin transport inp+GaAs

et al. 2015

View full text Add to dashboard Cite

In p + GaAs thin films, the effect of photoelectron degeneracy on spin transport is investigated theoretically and experimentally by imaging the spin polarization profile as a function of distance from a tightly-focussed light excitation spot. Under degeneracy of the electron gas (high concentration, low temperature), a dip at the center of the polarization profile appears with a polarization maximum at a distance of about 2 µm from the center. This counterintuitive result reveals that photoelectron diffusion depends on spin, as a direct consequence of the Pauli principle. This causes a concentration dependence of the spin stiffness while the spin dependence of the mobility is found to be weak in doped material. The various effects which can modify spin transport in a degenerate electron gas under local laser excitation are considered. A comparison of the data with a numerical solution of the coupled diffusion equations reveals that ambipolar coupling with holes increases the steady-state photo-electron density at the excitation spot and therefore the amplitude of the degeneracy-induced polarization dip. Thermoelectric currrents are predicted to depend on spin under degeneracy (spin Soret currents), but these currents are negligible except at very high excitation power where they play a relatively small role. Coulomb spin drag and bandgap renormalization are negligible due to electrostatic screening by the hole gas.

show abstract

Section: Discussionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Effect of the Pauli principle on photoelectron spin transport inp+GaAs

et al. 2015

View full text Add to dashboard Cite

show abstract

“…For the preferred electron density in Ref. 37 (n e = 10 18 cm −3 ), we note that the SRT is suppressed down to a value shorter than what is required for the spontaneous spin amplification to appear under the electric fields where the charge Gunn effect appears. This fast damping of spin polarization overtakes the spontaneously generation process and makes it difficult to realize the spin Gunn effect in an n-type bulk GaAs system.…”

Section: Discussionmentioning

confidence: 94%

Multivalley spin relaxation inn-type bulk GaAs in the presence of high electric fields

Tong

2012

Phys. Rev. B

View full text Add to dashboard Cite

Multivalley spin relaxation in n-type bulk GaAs in the presence of high electric field is investigated from the microscopic kinetic spin Bloch equation approach with the and L valleys included. We show that the spin relaxation time decreases monotonically with the electric field, which differs from the two-dimensional case and is recognized due to to the cubic form of the Dresselhaus spin-orbit coupling of the valley in bulk. In addition to the direct modulation of the spin relaxation time, the electric field also strongly influences the density and temperature dependences of the spin relaxation. In contrast to the monotonic decrease with increasing lattice temperature in the field-free condition, the spin relaxation time is shown to decrease more slowly under the influence of the electric field and even to increase monotonically in the case with small electron density and high electric field. We even predict a peak in weakly doped samples under moderate electric field due to the anomalous lattice-temperature dependence of the hot-electron temperature. As for the L valleys, we show that instead of playing the role of a "drain"of the total spin polarization as in quantum-well systems, in bulk they serve as a "momentum damping area" that prevents electrons from drifting to higher momentum states in the valley. This tends to suppress the inhomogeneous broadening and hence leads to an increase of the spin relaxation time.

show abstract

“…19 and 6); and (ii) localization centers that are critical in the determination of the spin-relaxation mechanism. 6,11,12 Another fundamental issue that has not been explored until very recently, is the physics of spin-dependent electron many-body processes [20][21][22] and phase-space filling effects. 23,24 Due to the difficulties in the theoretical modeling and in the analysis of the experimental results, the spin relaxation mechanisms in the regime where these effects are important are not well known.…”

Section: Introductionmentioning

confidence: 99%

Pauli blockade of the electron spin flip in bulk GaAs

et al. 2007

View full text Add to dashboard Cite

By means of time-resolved optical orientation under strong optical pumping, the k-dependence of the electron spin-flip time (τ sf ) in undoped GaAs is experimentally determined. τ sf monotonically decreases by more than one order of magnitude when the electron kinetic energy varies from 2 to 30 meV. At the high excitation densities and low temperatures of the reported experiments the main spin-flip mechanism of the conduction band electrons is the Bir-Aronov-Pikus. By means of Monte-Carlo simulations we evidence that phase-space filling effects result in the blocking of the spin flip, yielding an increase of τ sf with excitation density. These effects obtain values of τ sf up to 30 ns at k ≈ 0, the longest reported spin-relaxation time in undoped GaAs in the absence of a magnetic field. PACS number(s): 72.25. Rb, 72.25.Fe, 71.35.Ee, 78.47.+p

show abstract

Spin Gunn Effect

Cited by 33 publications

References 22 publications

Effect of the Pauli principle on photoelectron spin transport inp+GaAs

Effect of the Pauli principle on photoelectron spin transport inp+GaAs

Multivalley spin relaxation inn-type bulk GaAs in the presence of high electric fields

Pauli blockade of the electron spin flip in bulk GaAs

Contact Info

Product

Resources

About