BardeenCooperSchrieffer BCS

1
Superconductor/ Normal metal tunneling
gap
Bardeen-Cooper-Schrieffer (BCS) Density of states
near EF Phys. Rev. 108 1175 (1957) (Nobel
Prize, 1972)
Thermal broadening
2
Giaever, Phys. Rev. Lett., 5, 147 (1960) (Nobel
Prize 1973)
4.2 K H0.27T
1.6 K, H0T
Al-Al2O3-Pb (Normal-Insulator-Superconductor TJ)
3
Superconductor/ Normal metal tunneling w/
Magnetic Field
Meservey et al., PRB 7 318 (1973)
4
H0T
H4.3T
Meservey, PRB 11 4224 (1975)
Al-Al2O3-Ag
5
Meservey, PRL 25 1270 (1970)
6
Superconductor/ Ferromagnet tunneling w/ Magnetic
Field
7
Fe40 Co35 Ni23
8
Magnetic Tunnel Junctions
9
Room Temp
Moodera, PRL 74 3273 (1995)
10
Energy Model for a Metal
Energy
Bulk electron
11
Spin-Polarized Inverse Photo-Emission
Donath, Surf. Sci., 287/288 722 (1993)
12
Spin-Polarized Inverse Photo-Emission
Donath, Surf. Sci., 287/288 722 (1993)
13
Spin-Resolved Photo-Emission
Grobli et al PRB 51 2945 (1995)
14
Spin-Resolved Photo-Emission
Grobli et al PRB 51 2945 (1995)
15
Si-Au-Ge Metal-Base Transistor Schottky Barrier
Crowell, Sze PRL 15 659 (1965) Au mfp 23nm _at_ RT
16
Metal-Semiconductor Interface
conduction
Fermi Energy
n-type
valence
17
Electrical Rectification
n-type semiconductor
Schottky Barrier
Fermi Energy
metal
18
Spin-Valve Transistor
Vacuum-bonding
TEM
19
Light polarization / analysis
50
unpolarized
polarizer
20
Spin-Valve Transistor
21
Spin-Valve Transistor
Monsma et al, PRL 74 5260 (1995)
22
Tunnel-Junction Hot Electron Injection
Carver Mead, JAP, 32 646 (1961)
23
Ballistic Electron Emission
barrier
n-type Semiconductor
emitter
SB
base
Tunnel junction
24
Tunnel barrier

• n-type Semiconductor

emitter
Ferromagnetic multilayer base
Spin-Valve Transistor
25
Spin-Valve Transistor
FM1Co FM2 NiFe
77K
Appelbaum et al., APL 83 4571
26
Ballistic Electron Magnetic Microscopy
Haq et al, JAP 95 6930 (2004)
Rippard and Buhrman, APL 75 1001 (1999) APL 77
1357 (2000)
27
Magnetic Tunnel Transistor
Van Dijken, APL 80 3364 (2002)
28
Ballistic Spin Filter
Jiang, et al, PRL 90 256603 (2003)
29
Internal Photo-Emission (IPE)
photon
n-type Semiconductor

• Metal base

Fermi Energy
30
Spin-Valve Photo-Diode
hot electron
Semi- Conductor Collector
Sub-bandgap photon
FM1
FM2
Ip
31
Spin-Valve Photodiode
Optical attenuation
Hot-electron attenuation
Appelbaum et al., APL 83 3737 (2003)
32
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