Bulletin of the American Physical Society
Unconditional polarization qubit quantum memory at room temperature
Mehdi Namazi, Connor Kupchak, Bertus Jordaan, Reihaneh Shahrokhshahi, Eden V. Figueroa
Abstract
Here we study how the optical response of cold atomic environments is transformed by the motion of atoms at room temperature and consequently characterize the optimal performance of room temperature quantum light-matter interfaces. Our findings enable us to attain complete quantum memory operation for polarization qubits in a warm $^{87}$Rb atomic vapor with an average fidelity of $86.6\pm 0.6\%$, thereby defeating any classical strategy exploiting the non-unitary character of the memory efficiency. Our system significantly decreases the technological overhead required to achieve quantum memory operation and will serve as a building block for scalable and technologically simpler many-memory quantum machines.