A spin cell for spin current

Physical Review Letters

Volumn 90, Issue 25 I, 2003, Pages 2583011-2583014

  Sun, Qing Feng ^a,b   Guo, Hong ^a,b   Wang, Jian ^c  

^a MCGILL UNIVERSITY   (Canada)

^b INSTITUTE OF GEOLOGY AND GEOPHYSICS   (China)

^c UNIVERSITY OF HONG KONG   (Hong Kong)

Author keywords

[No Author keywords available]

Indexed keywords

ELECTRIC CHARGE; MAGNETIC FIELD EFFECTS; MAGNETIC MATERIALS; PHOTONS;

SPIN CURRENTS;

SEMICONDUCTOR QUANTUM DOTS;

EID: 0042768600     PISSN: 00319007     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (15)

1. S. A. Wolf et al., Science 294, 1488 (2001).
2. G. A. Prinz, Science 282, 1660 (1998).
3. There has been some work on the spin-current generation by a rotating magnetic field in a unipole device. A unipole system, however, cannot function as a spin cell because it cannot complete a spin circuit. See A. Brataas, Y. Tserkovnyak, G. E. W. Bauer, and B. I. Halperin, Phys. Rev. B 66, 060404 (2002); B. Wang, J. Wang, and H. Guo, ibid. 67, 092408 (2003).
4. There has been some work on the spin-current generation by a rotating magnetic field in a unipole device. A unipole system, however, cannot function as a spin cell because it cannot complete a spin circuit. See A. Brataas, Y. Tserkovnyak, G. E. W. Bauer, and B. I. Halperin, Phys. Rev. B 66, 060404 (2002); B. Wang, J. Wang, and H. Guo, ibid. 67, 092408 (2003).
5. A.-P. Jauho, N. S. Wingreen, and Y. Meir, Phys. Rev. B 50, 5528 (1994).
6. T. H. Oosterkamp et al., Nature (London) 395, 873 (1998).
7. N. S. Wingreen, A.-P. Jauho, and Y. Meir, Phys. Rev. B 48, 8487 (1993).
8. r = 0. In this approximation the level renormalization has been neglected. Because our system is in the Coulomb blockade regime, the level renormalization is very small and this approximation is reasonable. If the level renormalization is included, it does not affect the working principle of the spin cell.
9. Q.-f. Sun, J. Wang, and T.-h. Lin, Phys. Rev. B 59, 13126 (1999).
10. α, this Dyson equation is not exact, but is a good approximation.
11. g which makes the spin-motive force slightly different for spin-up and spin-down electrons, we can still obtain a spin current with zero charge current.
12. L accordingly.
13. T. H. Oosterkamp et al., Phys. Rev. Lett. 78, 1536 (1997).
14. L. P. Kouwenhoven et al., Phys. Rev. Lett. 73, 3443 (1994).
15. In order to calibrate experimental conditions at the spin-cell operating point, one needs a method to detect spin current outside the spin cell. Recently, Hirsch has advanced a theoretical idea for this purpose which works even in the absence of a charge current: J. E. Hirsch, Phys. Rev. Lett. 83, 1834 (1999). Moreover, the detection can be made easier if we allow and then detect a small charge current that flows through the spin cell, using the two panels of Fig. 2 as a "map" between the charge and spin currents.