OPNMR — a local probe of spin physics

Dementyev, Anatoly; Khandelwal, P.; Kuzma, N. N.; Barrett, Sean; Pfeiffer, L. N.; West, K. W.

doi:10.1016/s0038-1098(01)00235-6

Cited by 15 publications

(12 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In conventional NMR, the signal from the substrate always dominates that of the quantum wells unless specific relaxation properties of nuclei in the quantum wells are exploited [19][20][21]. Optical pumping combined with conventional detection [6,[22][23][24] can increase the signal contributions from quantum films to levels comparable to that of the substrate.…”

Section: Multiple Quantum Wellsmentioning

confidence: 99%

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells

Eickhoff

Suter

2004

Journal of Magnetic Resonance

View full text Add to dashboard Cite

Section: Multiple Quantum Wellsmentioning

confidence: 99%

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells

Eickhoff

Suter

2004

Journal of Magnetic Resonance

View full text Add to dashboard Cite

“…The latter are commonly used in all-optical NMR experiments, 6,7 while the former are used in optically pumped NMR experiments in the quantum Hall regime. [8][9][10][11][12] …”

Section: Introductionmentioning

confidence: 99%

Electron/nuclear spin domain walls in quantum Hall systems

Mitra

Girvin

2003

Phys. Rev. B

View full text Add to dashboard Cite

We propose experiments that can be done using both optically pumped NMR and the technique of all-optical NMR for creating spatially modulated nuclear-spin profiles. Due to the hyperfine coupling these would appear as spatially modulated Overhauser fields for the electrons that could have an amplitude large enough to cancel or even reverse the external Zeeman field at some places. We discuss two-dimensional electron-gas transport in the quantum Hall regime at filling factor ϭ1 and demonstrate the existence of collective modes and topological excitations induced in the electron gas by various nuclear-spin patterns. We calculate the 1/T 1 relaxation rate of the nuclear spins due to coupling with these low-lying collective modes and also discuss how transport and the low-energy modes would be affected by spin-orbit coupling in GaAs quantum wells grown in the ͓001͔ and ͓110͔ directions.

show abstract

“…Into these calculations go the noncanonical, nonconstant, density of states peculiar to this Hamiltonian. These results are compared to experiments of Dementyev et al, 18 who measured P and 1/T 1 at zero and a 38.3°tilt for a range of temperatures. They had pointed out that attempts to fit all four graphs with a standard Hamiltonian ͑with a mass m and Stoner coupling J) led to four disjoint set of values.…”

Section: Introductionmentioning

confidence: 67%

“…First consider Dementyev et al 18 From their data point Pϭ0.75 for BϭB Ќ ϭ5.52 T at 300 mK, I deduce ϭ1.75. ͑160͒…”

Section: Comparison To Experimentsmentioning

confidence: 99%

Hamiltonian theory of gaps, masses, and polarization in quantum Hall states

Shankar

2001

Phys. Rev. B

View full text Add to dashboard Cite

In two short papers I had described an extension, to all length scales, of the Hamiltonian theory of composite fermions ͑CF͒ that Murthy and I developed for the infrared, and applied it to compute finite-temperature quantities for quantum Hall fractions. I furnish details of the extended theory and apply it to Jain fractions ϭp/(2psϩ1). The explicit operator description in terms of the CF allows one to answer quantitative and qualitative issues, some of which cannot even be posed otherwise. I compute activation gaps for several potentials, exhibit their particle-hole symmetry, the profiles of charge density in states with a quasiparticle or hole ͑all in closed form͒, and compare to results from trial wave functions and exact diagonalization. The Hartree-Fock approximation is used, since much of the nonperturbative physics is built-in at tree level. I compare the gaps to experiment, and comment on the rough equality of normalized masses near half-and quarter-filling. I compute the critical fields at which the Hall system will jump from one quantized value of polarization to another, and the polarization and relaxation rates for half-filling as a function of temperature and propose a Korringa-like law. After providing some plausibility arguments, I explore the possibility of describing several magnetic phenomena in dirty systems with an effective potential, by extracting a free parameter describing the potential from one data point and then using it to predict all the others from that sample. This works to the accuracy typical of this theory ͑10-20 %͒. I explain why the CF behaves like a free particle in some magnetic experiments when it is not, what exactly the CF is made of, what one means by its dipole moment, and how the comparison of theory to experiment must be modified to fit the peculiarities of the quantized Hall problem.

show abstract

OPNMR — a local probe of spin physics

Cited by 15 publications

References 60 publications

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells

Electron/nuclear spin domain walls in quantum Hall systems

Hamiltonian theory of gaps, masses, and polarization in quantum Hall states

Contact Info

Product

Resources

About