Abstract
We present the experimental observation of a large exchange coupling J approximate to 300 mu eV between two P-31 electron spin qubits in silicon. The singlet and triplet states of the coupled spins are monitored in real time by a single-electron transistor, which detects ionization from tunnel-rate-dependent processes in the coupled spin system, yielding single-shot readout fidelities above 95%. The triplet to singlet relaxation time T-1 approximate to 4 ms at zero magnetic field agrees with the theoretical prediction for J-coupled P-31 dimers in silicon. The time evolution of the two-electron state populations gives further insight into the valley-orbit eigenstates of the donor dimer, valley selection rules and relaxation rates, and the role of hyperfine interactions. These results pave the way to the realization of two-qubit quantum logic gates with spins in silicon and highlight the necessity to adopt gating schemes compatible with weak J-coupling strengths.
Original language | English |
---|---|
Article number | 236801 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 112 |
Issue number | 23 |
DOIs | |
Publication status | Published - 9 Jun 2014 |
MoE publication type | A1 Journal article-refereed |
Keywords
- QUANTUM DOTS
- INFORMATION
- QUBIT
- GATE