Related papers: Anisotropic nuclear-spin diffusion in double quant…
We study a mechanism by which nuclear hyperpolarization due to the polarization transfer from a microwave-pulse-controlled electron spin is suppressed. From analytical and numerical calculations of the unitary dynamics of multiple nuclear…
We study the mechanism of dynamical nuclear spin polarization by hyperfine interaction in spin-blocked double quantum dot system. We calculate the hyperfine transition rates and solve the master equations for the nuclear spins.…
In a dynamic nuclear polarization experiment on a 40 mM solution of 4-amino-TEMPO in a 40:60 water/glycerol mixture, we have observed that the bulk dipolar reservoir is cooled to a spin temperature of 15.5 micro-K, following microwave…
In this work, we study a possibility to measure the transverse and longitudinal relaxation times of a collection of polarized nuclear spins located in the region of a quantum wire via its conductance. The interplay of an external in-plane…
Highly sensitive nuclear spin detection is crucial in many scientific areas including nuclear magnetic resonance spectroscopy (NMR), imaging (MRI) and quantum computing. The tiny thermal nuclear spin polarization represents a major obstacle…
We investigate the dynamic nuclear polarization from the hyperfine interaction between nonequilibrium electronic spins and nuclear spins coupled to them in semiconductor nanostructures. We derive the time and position dependence of the…
A highly asymmetric dynamic nuclear spin pumping is observed in a single self assembled InGaAs quantum dot subject to resonant optical pumping of the neutral exciton transition leading to a large maximum polarization of 54%. This dynamic…
Electrical polarization of nuclear spins is studied in a Corbino disk under a breakdown regime of the quantum Hall effect (QHE). Since the edge channels are completely absent in the Corbino disk, we conclude that the electric current…
Effects of both the dynamic nuclear polarization (DNP) created by circularly polarized light and the fluctuations of average nuclear spin in a quantum dot (QD) on the electron spin orientation are studied for singly negatively charged InP…
The study of nuclear magnetic resonance and nuclear spin-lattice relaxation was conducted in an asymmetrically doped to $n\sim1.8\times10^{11}$ cm$^{-2}$ 16 nm AlAs quantum well grown in the $[001]$-direction. Dynamic polarization of…
We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum well sample at 80 K. Diffusion of…
Hyperpolarized nanoparticles (NPs) offer high polarization levels with room temperature relaxation times exceeding half an hour. In this work, we demonstrate that the achievable hyperpolarization enhancement and relaxation (decay) time at…
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…
We report a new transport feature in a GaAs lateral double quantum dot that emerges only for magnetic field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP). This DNP signal appears in the Coulomb blockade regime…
We present an experimental study of the dynamics underlying the buildup and decay of dynamical nuclear spin polarization in a single semiconductor quantum dot. Our experiment shows that the nuclei can be polarized on a time scale of a few…
We propose a new method for dynamic nuclear polarisation in a quasi one-dimensional quantum wire utilising the spin-orbit interaction, the hyperfine interaction, and a finite source-drain potential difference. In contrast with current…
The dynamic polarization of nuclear spins interacting with resident electrons under resonant excitation of trions is studied in a nominally undoped GaAs/(Al,Ga)As quantum well. Unlike in common time-resolved pump-probe techniques, we used a…
We observe multiple stable states of nuclear polarization in a double quantum dot under conditions of electron spin resonance. The stable states can be understood within an elaborated theoretical rate equation model for the polarization in…
We theoretically study the nuclear spin dynamics driven by electron transport and hyperfine interaction in an electrically-defined double quantum dot (DQD) in the Pauli-blockade regime. We derive a master-equation-based framework and show…
Resonant laser scattering along with photon correlation measurements have established the atom-like character of quantum dots. Here, we present measurements which challenge this identification for a wide range of experimental parameters:…