Single electron Transport in diluted magnetic semiconductor quantum dots

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Single electron Transport in diluted magnetic
semiconductor quantum dots
J. Fernández-Rossier, R. Aguado
Department of Applied Physics, U. Alicante
SPAIN Material Science Institute of Madrid, CSIC
SPAIN
CdTe1 Mn
Gate Tuning Anisotropy
Spin dependent Capacitance
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Z19-1
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GaMnAs Single electron transistor
cond-mat/0602608 Coulomb blockade anisotropic
magnetoresistance Single electronics meets
spintronicsAuthorsJ. Wunderlich et al.
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Y. Léger et al., PRL 95, 047403 (05) L. Besombes
et al. PRL 93, 207403 (04)
Single ExcitonSpectroscopy
Mn(2) S5/2 2S16
PL Intensity
1 Mn per dot
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Heisenberg
STSeM
Mz
Ising
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Single exciton spectroscopy (1 Mn dot)
EXPERIMENTS Y. Léger et al. PRL 95, 047403 (05)
WE UNDERSTAND ehMn
THEORY J. Fernández-Rossier, PRB73, 045301 (06)
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Theory I The dot STATES
NUMERICAL DIAGONALIZATION
STATES WITH a FIXED NUMBER of CARRIERS
(Controlled By Gate Voltage)
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GATE CONTROL of Magnetic Anisotropy
ST
Mz
Ising
Heisenberg
ZXX
Free
HH
LH
Q-1
Q0
Q1
Q3
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Theory Single electron transport
Density matrix (Vg, Vb)
MASTER EQUATION
Scattering Rates
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CHARGING the dot
E
Q2
Q1
Q0
VG
Q
G
Q2
Q1
Q0
VG
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CHARGING the dot
Spin dependent CHARGING ENERGY
3 PEAKS instead of 1 !!
S2
S3
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E
VG
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E
VG
13
E
VG
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E
Q0
VG
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E
Q1/3
VG
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E
Q2/3
VG
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E
Q3/3
VG
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Inelastic single spin spectroscopy
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CONCLUSIONS
Electric Tuning of magnetic anisotropy
SPIN conditional charging energy
Q1
Q3
Mz
Ising
ZXX
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