Quantum Spin Lenses in Atomic Arrays

September 26, 2017

A quantum bit stored in the spin excitation of an atomic cloud could be "focused" onto the quantum state of a single atom. (Illustration and copyright by IQOQI/Harald Ritsch).*

A future quantum computer might use photonic qubits to move information around, but the qubits need to be transferred to a stationary medium such as atoms to perform computations. Given the weakness of the light-matter interaction, the transfer often requires a large ensemble of atoms, which can collectively take on a single photonic qubit. However, standard quantum logic operations are impractical with large ensembles and work best with one atom per qubit. Now an international team of physicists, including Prof. Mikhail Lukin, has proposed techniques to focus a quantum state spread over many atoms down to nearly a single atom. These techniques could allow multiple photonic qubits to be transferred into a quantum memory made of single-qubit atoms.

Continue reading the Synopsis by David Ehrenstein,"A Lens to Focus Spins," in Physics, September 20, 2017. https://physics.aps.org/synopsis-for/10.1103/PhysRevX.7.031049.

*Also see the original paper:
A.W. Glaetzle, K. Ender, D.S. Wild, S. Choi, H. Pichler, M.D. Lukin, and P. Zoller, "Quantum Spin Lenses in Atomic Arrays," Phys. Rev. X 7, 031049 (20 Sep 2017) DOI: https://doi.org/10.1103/PhysRevX.7.031049.