Borda László, Zaránd Gergely, Hofstetter Walter, Halperin B I, von Delft Jan
Sektion Physik and Center for Nanoscience, LMU München, Theresienstrasse 37, 80333 München, Germany.
Phys Rev Lett. 2003 Jan 17;90(2):026602. doi: 10.1103/PhysRevLett.90.026602.
We study a symmetrical double quantum dot (DD) system with strong capacitive interdot coupling using renormalization group methods. The dots are attached to separate leads, and there can be a weak tunneling between them. In the regime where there is a single electron on the DD the low-energy behavior is characterized by an SU(4)-symmetric Fermi liquid theory with entangled spin and charge Kondo correlations and a phase shift pi/4. Application of an external magnetic field gives rise to a large magnetoconductance and a crossover to a purely charge Kondo state in the charge sector with SU(2) symmetry. In a four-lead setup we find perfectly spin-polarized transmission.
我们使用重整化群方法研究了具有强电容性点间耦合的对称双量子点（DD）系统。这些量子点连接到单独的引线，并且它们之间可能存在弱隧穿。在DD上存在单个电子的情况下，低能行为由具有纠缠自旋和电荷近藤关联以及π/4相移的SU(4)对称费米液体理论来表征。施加外部磁场会导致大的磁电导，并在具有SU(2)对称性的电荷扇区中转变为纯电荷近藤态。在四引线设置中，我们发现了完全自旋极化的传输。
