Abstract
The recent advances in manipulating electronic spins in semiconductors provide a strong incentive for understanding the dynamics and transport properties of spin-based semiconducting electronics [1, 2, 3]. There has been a great deal of effort pursuing spin injection in high mobility but low dimensionality systems where spin transport is expected to be enhanced. However, most of the studies on spin transport and spin precession has been based on spin diffusive transport [4, 5]. For submicrons devices, where electronic mean free paths can easily exceed the length of the device, transport is in the ballistic regime. Furthermore, in the case of narrow conductors, only a few channels are involved in the spin transport and interchannel scattering becomes inconsequential and the electron can propagate phase coherently. It is at present unclear how the spatial part of the wavefunction can affect its spin counterpart. Indeed the quantum equation of motion for a spin in a magnetic field B is
where S and J are the spin density and spin-current density operators respectively and g, μ B are the gyromagnetic factor and Bohr magneton. In absence of spin flip scattering, the previous equation remains valid in a semiclassical sense where the operators are replaced by their expectation values. This raises the question, “Does phase coherence affect spin dynamics?” In this paper, we investigate this question and answer by the affirmative. Using a scattering approach, we study spin dynamics in a double barrier system. The continuous transition from fully coherent to fully incoherent propagation is described by a conceptually simple approach presented by Buttiker [6, 7]. In this model, incoherent propagation is achieved by inserting localized phase randomizing scatterers between elastic scatterers. Our results, which describe spin transport in the partially coherent regime, illustrate the importance of quantum effects. We show that quantum interference between multiples partial waves shifts the semiclassical spin resonance. Moreover, we demonstrate that spin and charge can mix, a phenomena with no classical analog.
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
S. Datta and B. Das, Appl. Phys. Lett. 56, 665 (1990).
D.D. Awschalom, D. Loss and D. Samarth, Semiconductor Spintronics and Quantum Computation, Springer Berlin, (2002) and references therein.
J.M. Kikkawa and D.D. Awschalom, Science, 287, 473 (2000); R. K. Kawakami et. al., Science, 294, 131 (2001).
M. Johnson, Science 260, 320 (1993).
F.J. Jedema, A.T. Filip, B.J. van Wess, Nature 410, 345 (2001).
M. Buttiker, Phys. Rev. B33, 3020 (1986); IBM J. Res. Dev. 32, 63 (1988).
I. Knittle, F. Gagel and M. Schreiber, Phys. Rev. B. 60, 916 (1999).
I. Malajovich, J.M. Kikkawa, D.D. Awschalom, J.J. Berr and N. Samarth, Phys. Rev. Lett. 84, 1015 (2000).
M. Johnson, R.H. Silsbee, Phys. Rev. B 37, 5712 (1988).
S. Datta, Electronic Transport in Mesoscopic Systems, Cambridge University Press, Cambridge, (1995).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2003 Springer Science+Business Media Dordrecht
About this paper
Cite this paper
Veillette, M.Y. (2003). Phase Coherence and Spin Dynamics. In: Fazio, R., Gantmakher, V.F., Imry, Y. (eds) New Directions in Mesoscopic Physics (Towards Nanoscience). NATO Science Series, vol 125. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-1021-4_21
Download citation
DOI: https://doi.org/10.1007/978-94-007-1021-4_21
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-1665-3
Online ISBN: 978-94-007-1021-4
eBook Packages: Springer Book Archive