Spin degeneracy and conductance fluctuations in open quantum dots.
نویسندگان
چکیده
The dependence of conductance fluctuations on parallel magnetic field is used as a probe of spin degeneracy in open GaAs quantum dots. The variance of fluctuations at high parallel field is reduced from the low-field variance (with broken time-reversal symmetry) by factors ranging from roughly 2 in a 1 microm (2) dot to greater than 4 in 8 microm (2) dots. The factor of 2 is expected for Zeeman splitting of spin-degenerate channels. A possible explanation for the larger suppression based on field-dependent spin-orbit scattering is proposed.
منابع مشابه
SPIN TRANSPORT MEASUREMENTS IN GaAs QUANTUM DOTS
This thesis explores the spin dynamics of lateral quantum dots in GaAs/AlGaAs heterostructures, including the first demonstration of a geometry capable of measuring mesoscopic spin currents. The term “quantum dot” as used in this thesis refers to partiallyconfined regions connected to two leads by quantum point contacts. Because the quantum dots investigated in these experiments are gate-tunabl...
متن کاملKondo effect in single-molecule spintronic devices
We study the Kondo effect in a quantum dot or a single molecule coupled to ferromagnetic leads. Spin-dependent quantum charge fluctuations in the dot induce the lifting of the spin degeneracy of the dot. It leads to the dot’s level spin splitting observed in the nonequilibrium transport as a splitting of a zero-bias anomaly in the differential conductance. We discuss basic properties of this ef...
متن کاملCoherent tunnelling through two quantum dots with Coulomb interaction
The coherent conductance and current is calculated through two quantum dots using the Hubbard model for a single level per spin. The occurrence of negative differential conductance is demonstrated. The Ohmic conductance is calculated for dots with equally spaced levels. Transport is determined by matching energy levels, even when they do not occur at the charge degeneracy points.
متن کاملاثر برهمکنشهای چهار اسپینی برروی سیمای فاز مدل هایزنبرگ J1-J2 پادفرومغناطیس اسپین 3/2 شبکه لانه زنبوری
In this study, the effect of four-spin exchanges between the nearest and next nearest neighbor spins of honeycomb lattice on the phase diagram of S=3/2 antiferomagnetic Heisenberg model is considered with two-spin exchanges between the nearest and next nearest neighbor spins. Firstly, the method is investigated with classical phase diagram. In classical phase diagram, in addition to Neel order,...
متن کاملElectron and nuclear spins in semiconductor quantum dots
The electron and nuclear spin degrees of freedom in two-dimensional semiconductor quantum dots are studied as important resources for such fields as spintronics and quantum information. The coupling of electron spins to their orbital motion, via the spinorbit interaction, and to nuclear spins, via the hyperfine interaction, are important for understanding spin-dynamics in quantum dot systems. T...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 86 10 شماره
صفحات -
تاریخ انتشار 2001