Gate control of dynamic nuclear polarization in GaAs quantum wells.
نویسندگان
چکیده
Gate control of dynamic nuclear polarization under optical orientation is demonstrated in a Schottky-gated n-GaAs/AlGaAs (110) quantum well by time-resolved Kerr rotation measurements. Spin relaxation of electrons due to mechanisms other than the hyperfine interaction is effectively suppressed as the donor induced background electron density is reduced from metallic to insulating regimes. Subsequent accumulation of photoexcited electron spins dramatically enhances dynamic nuclear polarization at low magnetic field, allowing us to tune nuclear spin polarization by external gate voltages.
منابع مشابه
The Effect of Exchange-Correlation Holes on the Temperature Dependent Dynamic Dielectric Function of Single-Layer Quantum Wells and Coupled Nanolayers
In this paper, for the first time we have studied theoretically the effect of exchange-correlation holes around electrons in GaAlAs/GaAs/GaAlAs nanostructure on the temperature-dependent dynamic dielectric function of two-dimensional electron gas by employing random phase, STLS and Hubbard approximations. Also, we have investigated another interesting system which is coupled quantum wells struc...
متن کاملNonequilibrium nuclear polarization and induced hyperfine and dipolar magnetic fields in semiconductor nanostructures
We investigate the dynamic nuclear polarization (DNP) caused by hyperfine coupling between nonequilibrium electronic spins and nuclear spins in semiconductor nanostructures. We derive the time and position dependence of the resulting hyperfine and dipolar magnetic fields. In GaAs quantum wells the induced nuclear spin polarization greatly exceeds the polarization of the electronic system that c...
متن کاملExchange control of nuclear spin diffusion in a double quantum dot.
The influence of gate-controlled two-electron exchange on the relaxation of nuclear polarization in small ensembles (N∼10(6)) of nuclear spins is examined in a GaAs double quantum dot system. Waiting in the (2,0) charge configuration, which has large exchange splitting, reduces the nuclear diffusion rate compared to that of the (1,1) configuration. Matching exchange to Zeeman splitting signific...
متن کاملQuenching of dynamic nuclear polarization by spin–orbit coupling in GaAs quantum dots
The central-spin problem is a widely studied model of quantum decoherence. Dynamic nuclear polarization occurs in central-spin systems when electronic angular momentum is transferred to nuclear spins and is exploited in quantum information processing for coherent spin manipulation. However, the mechanisms limiting this process remain only partially understood. Here we show that spin-orbit coupl...
متن کاملDynamic nuclear Overhauser shifts in Larmor beats from a quantum well
The significance of nuclear spin polarisation in time-resolved optical studies of III-V semiconductors is addressed. Electron Larmor beats in pump-probe reflectivity from a GaAs/AlGaAs quantum well show Overhauser shift of 0.7 T due to accumulated nuclear polarisation 〈I〉/I=0.065. This leads to precision values of electron g-factor, elucidates nuclear spin pumping and diffusion mechanisms in qu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 94 9 شماره
صفحات -
تاریخ انتشار 2005