Novel Architecture of Illuminable Variable Density Two-Dimensional Electron System S.Brandsen, J....
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Transcript of Novel Architecture of Illuminable Variable Density Two-Dimensional Electron System S.Brandsen, J....
Novel Architecture of Illuminable Variable Density Two-Dimensional Electron
SystemS.Brandsen, J. Pollanen, J.P. Eisenstein
Institute for Quantum Information and Matter (IQIM), Condensed Matter Physics, Caltech
L.N. Pfeiffer, K.W. WestPrinceton Univ., Dept. of Electrical Engineering
Outline
• Two-Dimensional Electron System: Collective electron states
• Question: Phenomena as a function of charge density?
• Illuminable Variable Density Two-Dimensional Electron System: Fabrication, Magnetotransport, Future Uses
Beyond single particle physics
Can we control interactions ?
A zoo of collective electron ground states!
VH
B - fi
eld
i
Vv=5/2
Characterization of 2DES
Etched n+ to depletion
μ2DES : 3x106 cm2/Vs, n2DES: 1.2x1011 carriers/cm2
R xx (Ω
)
Field Strength (Tesla) n+
GaAs
AlGaAs
Characterization of 2DES
Diffused Ni/Au/Ge Contacts
μ2DES : 3x106 cm2/Vs, n2DES: 1.2x1011 carriers/cm2
R xx (Ω
)
Field Strength (Tesla) n+
GaAs
AlGaAs
Initial Characterization
GaAs
AlGaAs
DiffusedNi/Au/Ge contacts
μ2DES : 3x106 cm2/Vs, n2DES: 1.2x1011 carriers/cm2
Known values
Fit Parameters
R xx (Ω
)
Field Strength (Tesla)
μn+: 3x104 cm2/Vsnn+ : 7.4x1012 carriers/cm2
Fabrication Procedure
n+AlGaAs
Diffused Ni/Au/Ge Contacts
GaAs
AlGaAs
Si Si Sin+ GaAs d
dopants2DES
GaAs
AlGaAs
Fabrication Procedure
n+AlGaAs
Shallow Pd/Au/Ge Contacts
GaAs
AlGaAs
Si Si Sin+ GaAs d
dopants2DES
GaAs
AlGaAs
Fabrication Procedure
n+AlGaAs
Shallow Pd/Au/Ge Contacts
GaAs
AlGaAs
Si Si Sin+ GaAs d
dopants2DES
GaAs
AlGaAs
Conclusions
• Development of illuminable high mobility, variable density 2DES
• Potential to explore the role of charge density in 2DES phenomena