Ultrafast quantum random access memory utilizing single Rydberg atoms in a Bose-Einstein condensate.
We propose a long-lived and rapidly accessible quantum memory unit, for which the operational Hilbert space is spanned by states involving the two macroscopically occupied hyperfine levels of a miscible binary atomic Bose-Einstein condensate and the Rydberg state of a single atom. It is shown that an arbitrary qubit state, initially prepared using a flux qubit, can be rapidly transferred to and from the trapped atomic ensemble in approximately 10 ns and with a large fidelity of 97%, via an effective two-photon process using an external laser for the transition to the Rydberg level. The achievable ultrafast transfer of quantum information therefore enables a large number of storage and retrieval cycles from the highly controllable quantum optics setup of a dilute ultracold gas, even within the typically very short flux qubit lifetimes of the order of microseconds.
Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, 151-747 Seoul, Korea.
Kelly R
KR
Patton
Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, 151-747 Seoul, Korea.
Uwe R
UR
Fischer