Solid-state quantum memory using the 31P nuclear spin

摘要: The transfer of information between the entities that do processing and memory is crucial — problematic for quantum computation. In classical systems can include a copying step, where errors be spotted corrected, but in fundamentally precluded. Morton et al. demonstrate technology could solve problem: coherent storage readout electron-spin elements based on nuclear spin. system utilizes phosphorus-31 spin donors silicon-28 crystal. acts as element faithfully store full state electron more than second, then it back to with about 90% efficiency. computation; challenging because process must remain at all times preserve nature information. This paper demonstrates different physical forms—for example memory—is central theme communication computation1, great effort2 taken protect integrity fragile bit (qubit). However, particularly challenging, information3. Here we superposition an ‘processing’ qubit nuclear-spin ‘memory’ qubit, using combination microwave radio-frequency pulses applied 31P isotopically pure 28Si crystal4,5. left timescale long compared decoherence time, coherently transferred spin, thus demonstrating solid-state memory. overall store–readout fidelity 90 per cent, loss attributed imperfect rotations, improved through use composite pulses6. coherence lifetime 5.5 K exceeds 1 s.