Single-shot ternary readout of two-electron spin states in a quantum dot using spin filtering by quantum Hall edge states



H. Kiyama, T. Nakajima, S. Teraoka, A. Oiwa, and S. Tarucha



We report on the single-shot readout of three two-electron spin states—a singlet and two triplet substates—whose z components of spin angular momentum are 0 and +1, in a gate-defined GaAs single quantum dot. The three spin states are distinguished by detecting spin-dependent tunnel rates that arise from two mechanisms: spin filtering by spin-resolved edge states and spin-orbital correlation with orbital-dependent tunneling. The three states form one ground state and two excited states, and we observe the spin relaxation dynamics among the three spin states.



PhysicalReview Letters: