Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures

Ashwin Ashok, Richard Akis, Dragica Vasileska, David K. Ferry

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The spontaneous spin polarization of a quantum point contact (QPC) formed by the lateral confinement of a high-mobility two-dimensional electron gas in a GaAs/AlGaAs split gate heterostrucrure is investigated. Self consistent calculations of the electronic structure of the QPC are performed using the spin-polarized density functional formalism of Kohn and Sham. Spin polarization occurs at low electron densities and exchange interaction is found to be the dominant mechanism driving the local spin polarization within the QPC. The cascading scattering matrix approach is utilized to compute the conductance and a conductance anomaly at ∼ 0.5 (2e2/h) has been observed. In addition to this, the sheet density dependence of the 0.7 conduction anomaly is investigated.

Original languageEnglish (US)
Title of host publication2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings
EditorsM. Laudon, B. Romanowicz
Pages17-20
Number of pages4
StatePublished - 2005
Event2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 - Anaheim, CA, United States
Duration: May 8 2005May 12 2005

Other

Other2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005
CountryUnited States
CityAnaheim, CA
Period5/8/055/12/05

Fingerprint

Spin polarization
Point contacts
Heterojunctions
Two dimensional electron gas
Exchange interactions
Electronic structure
Carrier concentration
Scattering

Keywords

  • 0.7 structure
  • 2DEG
  • LDA
  • QPC

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Ashok, A., Akis, R., Vasileska, D., & Ferry, D. K. (2005). Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures. In M. Laudon, & B. Romanowicz (Eds.), 2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings (pp. 17-20)

Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures. / Ashok, Ashwin; Akis, Richard; Vasileska, Dragica; Ferry, David K.

2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings. ed. / M. Laudon; B. Romanowicz. 2005. p. 17-20.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Ashok, A, Akis, R, Vasileska, D & Ferry, DK 2005, Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures. in M Laudon & B Romanowicz (eds), 2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings. pp. 17-20, 2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005, Anaheim, CA, United States, 5/8/05.
Ashok A, Akis R, Vasileska D, Ferry DK. Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures. In Laudon M, Romanowicz B, editors, 2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings. 2005. p. 17-20
Ashok, Ashwin ; Akis, Richard ; Vasileska, Dragica ; Ferry, David K. / Spin polarization in GaAs/Al0.24Ga<0.76As heterostructures. 2005 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2005 Technical Proceedings. editor / M. Laudon ; B. Romanowicz. 2005. pp. 17-20
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AB - The spontaneous spin polarization of a quantum point contact (QPC) formed by the lateral confinement of a high-mobility two-dimensional electron gas in a GaAs/AlGaAs split gate heterostrucrure is investigated. Self consistent calculations of the electronic structure of the QPC are performed using the spin-polarized density functional formalism of Kohn and Sham. Spin polarization occurs at low electron densities and exchange interaction is found to be the dominant mechanism driving the local spin polarization within the QPC. The cascading scattering matrix approach is utilized to compute the conductance and a conductance anomaly at ∼ 0.5 (2e2/h) has been observed. In addition to this, the sheet density dependence of the 0.7 conduction anomaly is investigated.

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