Collective Quantum Memory Activated by a Driven Central Spin
Physical Review Letters
American Physical Society (APS)
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Denning, E. V., Gangloff, D., Atatüre, M., Mørk, J., & Le Gall, C. (2019). Collective Quantum Memory Activated by a Driven Central Spin. Physical Review Letters, 123 (14. 140502)https://doi.org/10.1103/physrevlett.123.140502
Coupling a qubit coherently to an ensemble is the basis for collective quantum memories. A single driven electron in a quantum dot can deterministically excite low-energy collective modes of a nuclear spin ensemble in the presence of lattice strain. We propose to gate a quantum state transfer between this central electron and these low-energy excitations—spin waves—in the presence of a strong magnetic field, where the nuclear coherence time is long. We develop a microscopic theory capable of calculating the exact time evolution of the strained electron-nuclear system. With this, we evaluate the operation of quantum state storage and show that fidelities up to 90% can be reached with a modest nuclear polarization of only 50%. These findings demonstrate that strain-enabled nuclear spin waves are a highly suitable candidate for quantum memory.
We thank E. Chekhovich for helpful discussions. This work was supported by the ERC PHOENICS grant (617985), the EPSRC Quantum Technology Hub NQIT (EP/M013243/1), and the Royal Society (RGF/EA/181068). D. A. G. acknowledges support from St. John’s College Title A Fellowship. E. V. D. and J. M. acknowledge funding from the Danish Council for Independent Research (Grant No. DFF-4181-00416). C. L. G. acknowledges support from a Royal Society Dorothy Hodgkin Fellowship.
UNIVERSITY OF OXFORD (FB EPSRC) (EP/M013243/1)
Royal Society (DHF\R1\180124)
Royal Society (RGF\EA\181068)
External DOI: https://doi.org/10.1103/physrevlett.123.140502
This record's URL: https://www.repository.cam.ac.uk/handle/1810/297955
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