Zobrazeno 1 - 10
of 134
pro vyhledávání: '"De Poortere, E."'
Autor:
Gokmen, T., Padmanabhan, Medini, Gunawan, O., Shkolnikov, Y. P., Vakili, K., De Poortere, E. P., Shayegan, M.
Publikováno v:
Phys. Rev. B 78, 233306 (2008)
We demonstrate that, in a quasi-two-dimensional electron system confined to an AlAs quantum well and occupying two conduction-band minima (valleys), a parallel magnetic field can couple to the electrons' orbital motion and tune the energies of the tw
Externí odkaz:
http://arxiv.org/abs/0811.3194
Publikováno v:
Physical Review Letter 100, 03660 (2008)
An AlAs two-dimensional electron system patterned with an anti-dot lattice exhibits a giant piezoresistance (GPR) effect, with a sign opposite to the piezoresistance observed in the unpatterned region. We trace the origin of this anomalous GPR to the
Externí odkaz:
http://arxiv.org/abs/0707.0153
Autor:
Bishop, N. C., Padmanabhan, M., Vakili, K., Shkolnikov, Y. P., De Poortere, E. P., Shayegan, M.
We report magnetotransport measurements of fractional quantum Hall states in an AlAs quantum well around Landau level filling factor nu = 3/2, demonstrating that the quasiparticles are composite Fermions (CFs) with a valley degree of freedom. By moni
Externí odkaz:
http://arxiv.org/abs/0706.1195
We report low-temperature resistance measurements in a modulation-doped, (311)A GaAs two-dimensional hole system as a function of applied in-plane strain. The data reveal a strong but anisotropic piezoresistance whose magnitude depends on the density
Externí odkaz:
http://arxiv.org/abs/0706.0736
We report direct measurements of the spin-orbit interaction induced spin-splitting in a modulation-doped GaAs two-dimensional hole system as a function of anisotropic, in-plane strain. The change in spin-subband densities reveals a remarkably strong
Externí odkaz:
http://arxiv.org/abs/cond-mat/0610096
Publikováno v:
Nature Physics 3, 388 - 391 (2007)
Using symmetry breaking strain to tune the valley occupation of a two-dimensional (2D) electron system in an AlAs quantum well, together with an applied in-plane magnetic field to tune the spin polarization, we independently control the system's vall
Externí odkaz:
http://arxiv.org/abs/cond-mat/0609493
We report ballistic transport measurements in a two-dimensional electron system confined to an AlAs quantum well and patterned with square antidot lattices of period $a = $0.6, 0.8, 1.0 and 1.5 $\mu$m. In this system two in-plane conduction-band vall
Externí odkaz:
http://arxiv.org/abs/cond-mat/0609110
Publikováno v:
Phys. Rev. B. 74, 155 436 (2006)
We report experimental results on a quantum point contact (QPC) device formed in a wide AlAs quantum well where the two-dimensional electrons occupy two in-plane valleys with elliptical Fermi contours. To probe the closely-spaced, one-dimensional ele
Externí odkaz:
http://arxiv.org/abs/cond-mat/0606272
Two-dimensional electrons in AlAs quantum wells occupy multiple conduction-band minima at the X- points of the Brillouin zone. These valleys have large effective mass and g-factor compared to the stan-dard GaAs electrons, and are also highly anisotro
Externí odkaz:
http://arxiv.org/abs/cond-mat/0606158
Publikováno v:
Phys. Rev. Lett. 97, 116803 (2006)
We report measurements of the quantum Hall state energy gap at avoided crossings between Landau levels originating from different conduction band valleys in AlAs quantum wells. These gaps exhibit an approximately linear dependence on magnetic field o
Externí odkaz:
http://arxiv.org/abs/cond-mat/0606072