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We show that the hyperfine mediated dynamics of heavy hole states confined in neutral self- assembled quantum dots leads to a nuclear spin diffusion mechanism. It is found that the oftentimes neglected effective heavy hole hyperfine…

Mesoscale and Nanoscale Physics · Physics 2014-03-04 Hugo Ribeiro , Franziska Maier , Daniel Loss

Dynamic nuclear polarization (DNP) is a promising strategy for generating a significantly increased non-thermal spin polarization in nuclear magnetic resonance (NMR) applications thereby circumventing the need for strong magnetic fields.…

Quantum Physics · Physics 2015-07-15 Alexander Karabanov , Daniel Wisniewski , Igor Lesanovsky , Walter Köckenberger

A quasi-classical theoretical description of polarization and relaxation of nuclear spins in a quantum dot with one resident electron is developed for arbitrary mechanisms of electron spin polarization. The dependence of the…

Strongly Correlated Electrons · Physics 2015-05-13 I. A. Merkulov , G. Alvarez , D. R. Yakovlev , T. C. Schulthess

We propose a nuclear-spin-polarization protocol in a general evolution-and-measurement framework. The protocol works in a spin-star configuration, where the central spin is coupled to the surrounding bath (nuclear) spins by flip-flop…

Quantum Physics · Physics 2022-12-07 Zhu-yao Jin , Jia-shun Yan , Jun Jing

Spin-blockaded quantum dots provide a unique setting for studying nuclear-spin dynamics in a nanoscale system. Despite recent experimental progress, observing phase-sensitive phenomena in nuclear spin dynamics remains challenging. Here we…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 M. S. Rudner , I. Neder , L. S. Levitov , B. I. Halperin

Nuclear spin polarization is typically generated in GaAs quantum point contacts (QPCs) when an out-of-plane magnetic field gives rise to spin-polarized quantum Hall edge states, and a voltage bias drives transitions between the edge states…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Y. Ren , W. Yu , S. M. Frolov , J. A. Folk , W. Wegscheider

A dynamical nuclear polarization scheme is studied in gated double dots. We demonstrate that a small polarization ($\sim 0.5%$) is sufficient to enhance the singlet decay time by two orders of magnitude. This enhancement is attributed to an…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Guy Ramon , Xuedong Hu

We have theoretically analyzed coherent nuclear-spin dynamics induced by electron transport through a quantum-dot spin valve. The hyperfine interaction between electron and nuclear spins in a quantum dot allows for the transfer of angular…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 Stefano Chesi , W. A. Coish

We present an extension of relativistic single-particle distribution function for weakly interacting particles at local thermodynamical equilibrium including spin degrees of freedom, for massive spin 1/2 particles. We infer, on the basis of…

Nuclear Theory · Physics 2015-06-15 F. Becattini , V. Chandra , L. Del Zanna , E. Grossi

A theoretical study of spin dynamics in non-relativistic particle beams with interacting angular momenta traversing static, spatially varying magnetic fields is presented. The computational framework evaluates sinusoidal magnetic field…

We propose a model for spectral diffusion of localized spins in semiconductors due to the dipolar fluctuations of lattice nuclear spins. Each nuclear spin flip-flop is assumed to be independent, the rate for this process being calculated by…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Rogerio de Sousa , S. Das Sarma

We experimentally demonstrate a method for obtaining nuclear spin hyperpolarization, that is, polarization significantly in excess of that expected for a thermal equilibrium. By exploiting a modified Overhauser process, we obtain more than…

Materials Science · Physics 2009-02-26 D. R. McCamey , J. van Tol , G. W. Morley , C. Boehme

We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anti-crossing of the singlet (S) and m_S=+1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. R. Petta , J. M. Taylor , A. C. Johnson , A. Yacoby , M. D. Lukin , C. M. Marcus , M. P. Hanson , A. C. Gossard

We propose a scalable and practical implementation of spin amplification which does not require individual addressing nor a specially tailored spin network. We have demonstrated a gain of 140 in a solid-state nuclear spin system of which…

Quantum Physics · Physics 2015-05-28 Makoto Negoro , Kenichiro Tateishi , Akinori Kagawa , Masahiro Kitagawa

Dynamic nuclear polarisation (DNP) refers to a class of techniques used to increase the signal in nuclear magnetic resonance measurements by transferring spin polarisation from ensembles of highly polarised electrons to target nuclear…

Quantum Physics · Physics 2020-12-24 L. T. Hall , D. A. Broadway , A. Stacey , D. A. Simpson , J-P. Tetienne , L. C. L. Hollenberg

The dynamic polarization of nuclear spins by photoexcited electrons is studied in a high quality GaAs/AlGaAs quantum well. We find a surprisingly high efficiency of the spin transfer from the electrons to the nuclei as reflected by a…

Mesoscale and Nanoscale Physics · Physics 2017-11-15 R. W. Mocek , V. L. Korenev , M. Bayer , M. Kotur , R. I. Dzhioev , D. O. Tolmachev , G. Cascio , K. V. Kavokin , D. Suter

We discuss the polarization dynamics during solid effect dynamic nuclear polarization (DNP) in a central spin model that consists of an electron surrounded by many nuclei. To this end we use a recently developed formalism and validate first…

Other Condensed Matter · Physics 2016-03-23 Daniel Wiśniewski , Alexander Karabanov , Igor Lesanovsky , Walter Köckenberger

The polarisation dynamics of nuclear spins weakly coupled to an NV center is highly sensitive to the parameters of the microwave control and the nuclear Larmor frequency. What is commonly regarded as a challenge, we propose here as a…

Quantum Physics · Physics 2018-10-24 Q. Chen , Z. -Y. Wang , B. Tratzmiller , I. Schwartz , M. B. Plenio

Hyperfine interactions between electron and nuclear spins in the quantum Hall regime provide powerful means for manipulation and detection of nuclear spins. In this work we demonstrate that significant changes in nuclear spin polarization…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Y. Q. Li , V. Umansky , K. von Klitzing , J. H. Smet

Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels…

Mesoscale and Nanoscale Physics · Physics 2010-08-23 M. S. Rudner , L. S. Levitov