Abstract
The Rydberg blockade mechanism is now routinely considered for entangling qubits encoded in clock states of neutral atoms. Challenges towards implementing entangling gates with high fidelity include errors due to thermal motion of atoms, laser amplitude inhomogeneities, and imperfect Rydberg blockade. We show that adiabatic rapid passage by Rydberg dressing provides a mechanism for implementing two-qubit entangling gates by accumulating phases that are robust to these imperfections. We find that the typical error in implementing a two-qubit gate, such as the controlled phase gate, is dominated by errors in the single-atom light shift, and that this can be easily corrected using adiabatic dressing interleaved with a simple spin echo sequence. This results in a two-qubit Mølmer-Sørensen gate. A gate fidelity ∼0.995 is achievable with modest experimental parameters and a path to higher fidelities is possible for Rydberg states in atoms with a stronger blockade, longer lifetimes, and larger Rabi frequencies.
| Original language | English |
|---|---|
| Article number | 030301 |
| Journal | Physical Review A |
| Volume | 101 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2020 |
| Externally published | Yes |
Funding
We thank Christiane Koch and David Weiss for helpful discussions. This work was supported by NSF Grants No. PHY-1606989 and No. PHY-1630114, the Laboratory Directed Research and Development program at Sandia National Laboratories, and by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under Projects No. 20190494ER and No. 20200015ER. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy National Nuclear Security Administration under Contract No. DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the U.S. Government.