Evidence of spontaneous spin polarization in the two-dimensional electron gas

A. R. Goñi; P. Giudici; F. A. Reboredo; C. R. Proetto; C. Thomsen; K. Eberl; M. Hauser

doi:10.1103/PhysRevB.70.195331

Evidence of spontaneous spin polarization in the two-dimensional electron gas

A. R. Goñi, P. Giudici, F. A. Reboredo, C. R. Proetto, C. Thomsen, K. Eberl, M. Hauser

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Density-functional calculations using an exact exchange potential for a two-dimensional electron gas (2DEG) formed in a GaAs single quantum well predict the existence of a spin-polarized phase, when an excited subband becomes slightly populated. Direct experimental evidence is obtained from low-temperature and low-excitation power photoluminescence (PL) spectra, which display the sudden appearance of a sharp emission peak below the energy of the optical transition from the first excited electron subband upon its occupation. The behavior of this PL feature in magnetic fields applied in-plane as well as perpendicular to the 2DEG indicate the formation of spin-polarized domains in the excited subband with in-plane magnetization. The strong enhancement of exchange-vertex corrections observed in inelastic light scattering spectra by spin-density excitations of a slightly occupied first-excited subband also speaks for the appearance of magnetic ordering.

Original language	English
Article number	195331
Pages (from-to)	1-6
Number of pages	6
Journal	Physical Review B - Condensed Matter and Materials Physics
Volume	70
Issue number	19
DOIs	https://doi.org/10.1103/PhysRevB.70.195331
State	Published - Nov 2004
Externally published	Yes

Funding

We thank F. Guinea for inspiring discussions and W. Dietsche for assistance with the sample design and growth. A.R.G. acknowledges support from ICREA. F.A.R. acknowledges the auspices of the U.S. Dept. of Energy at the University of California/Lawrence Livermore National Lab under Contract No. W-7405-Eng-48. P.G. thanks the DAAD for financial support. This work was supported in part by the DFG in the framework of Sfb 296 and by CONICET under Grant No. PIP 02753/00.

Funders	Funder number
U.S. Dept. of Energy
University of California/Lawrence Livermore National Lab	W-7405-Eng-48
Deutscher Akademischer Austauschdienst
Deutsche Forschungsgemeinschaft
Consejo Nacional de Investigaciones Científicas y Técnicas	PIP 02753/00
Institució Catalana de Recerca i Estudis Avançats

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AU - Goñi, A. R.

AU - Giudici, P.

AU - Reboredo, F. A.

AU - Proetto, C. R.

AU - Thomsen, C.

AU - Eberl, K.

AU - Hauser, M.

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Evidence of spontaneous spin polarization in the two-dimensional electron gas

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