72
2 Basic Elements of Spintronics
(i) efficient spin injection and charge conduction into and out of the
semiconductor.
(ii) poor spin injection but charge conduction into and out of a
semiconductor.
(iii) efficient spin injection but charge conduction for one bias polarity,
not the other.
(f) In case of Ni, spin polarization is 11%. The number of spin-up electrons
is equal to
(i) 2.2 times the number of spin-down electrons.
(ii) 1.2 times the number of spin-down electrons.
(iii) 3.2 times the number of spin-down electrons.
(g) Let us consider an ensemble of electrons drifting and diffusing in a
solid and the electrons velocity changes as delta function. Which of the
following statement is correct?
(i) spin relaxation rate is high for D’yakonov-Perel’ mechanism.
(ii) spin relaxation rate is low for D’yakonov-Perel’ mechanism.
(iii) spin relaxation rate is high for Elliott–Yafet mechanism.
(h) In case of 3d transition metals,
(i) Fermi level intersects only 4s band.
(ii) Fermi level intersects only 3d band.
(iii) Fermi level intersects both 3d and 4s bands.
(i) Spin filtering effect in ferromagnet arises
(i) minority spin electrons have larger absorption coefficient than
majority spin electrons in spin-dependent energy band.
(ii) minority spin electrons have smaller absorption coefficient than
majority spin electrons in spin-dependent energy band.
(iii) minority and majority spin electrons have same absorption coefficient in spin-dependent energy band.
References
I. Appelbaum, B. Huang, D.J. Monsma, Electronic measurement and control of spin transport in
silicon. Nature 447, 295 (2007)
S. Bandyopadhyay, M. Cahay, Introduction to Spintronics (CRC Press Taylor & Francis 2008);
Electron spin for classical information processing: a brief survey of spin-based logic devices,
gates and circuits. Nanotechnology 20, 412001 (2009)
Y. Bychkov, E.I. Rashba, Oscillatory effects and the magnetic susceptibility of carriers in inversion
layers. J. Phys. C 17, 6039 (1984)
G. Dresselhaus, Spin orbit coupling effects in zinc blende structures. Phys. Rev. 100, 580 (1955)
A. Hirohataa, K. Yamadab et al., Review on spintronics: principles and device applications. J. Magn.
Magn. Mater. 509, 166711 (2020)
2 Basic Elements of Spintronics
(i) efficient spin injection and charge conduction into and out of the
semiconductor.
(ii) poor spin injection but charge conduction into and out of a
semiconductor.
(iii) efficient spin injection but charge conduction for one bias polarity,
not the other.
(f) In case of Ni, spin polarization is 11%. The number of spin-up electrons
is equal to
(i) 2.2 times the number of spin-down electrons.
(ii) 1.2 times the number of spin-down electrons.
(iii) 3.2 times the number of spin-down electrons.
(g) Let us consider an ensemble of electrons drifting and diffusing in a
solid and the electrons velocity changes as delta function. Which of the
following statement is correct?
(i) spin relaxation rate is high for D’yakonov-Perel’ mechanism.
(ii) spin relaxation rate is low for D’yakonov-Perel’ mechanism.
(iii) spin relaxation rate is high for Elliott–Yafet mechanism.
(h) In case of 3d transition metals,
(i) Fermi level intersects only 4s band.
(ii) Fermi level intersects only 3d band.
(iii) Fermi level intersects both 3d and 4s bands.
(i) Spin filtering effect in ferromagnet arises
(i) minority spin electrons have larger absorption coefficient than
majority spin electrons in spin-dependent energy band.
(ii) minority spin electrons have smaller absorption coefficient than
majority spin electrons in spin-dependent energy band.
(iii) minority and majority spin electrons have same absorption coefficient in spin-dependent energy band.
References
I. Appelbaum, B. Huang, D.J. Monsma, Electronic measurement and control of spin transport in
silicon. Nature 447, 295 (2007)
S. Bandyopadhyay, M. Cahay, Introduction to Spintronics (CRC Press Taylor & Francis 2008);
Electron spin for classical information processing: a brief survey of spin-based logic devices,
gates and circuits. Nanotechnology 20, 412001 (2009)
Y. Bychkov, E.I. Rashba, Oscillatory effects and the magnetic susceptibility of carriers in inversion
layers. J. Phys. C 17, 6039 (1984)
G. Dresselhaus, Spin orbit coupling effects in zinc blende structures. Phys. Rev. 100, 580 (1955)
A. Hirohataa, K. Yamadab et al., Review on spintronics: principles and device applications. J. Magn.
Magn. Mater. 509, 166711 (2020)