State-dependent lattices for quantum computing with alkaline-earth-metal atoms

TL;DR

This paper proposes a novel quantum computing scheme using state-dependent optical lattices with alkaline-earth-metal atoms, enabling improved gate operations through nuclear-spin-dependent interactions and lossy blockade mechanisms.

Contribution

It introduces a new approach to quantum gates with alkaline-earth atoms using near-resonant coupling to metastable states, differing from previous independent lattice schemes.

Findings

Demonstrates feasibility of nuclear-spin-dependent lattices for quantum gates

Shows how to utilize collisional losses for gate operations

Provides detailed implementation strategies for alkali-earth atom quantum computing

Abstract

Recent experimental progress with Alkaline-Earth atoms has opened the door to quantum computing schemes in which qubits are encoded in long-lived nuclear spin states, and the metastable electronic states of these species are used for manipulation and readout of the qubits. Here we discuss a variant of these schemes, in which gate operations are performed in nuclear-spin-dependent optical lattices, formed by near-resonant coupling to the metastable excited state. This provides an alternative to a previous scheme [A. J. Daley, M. M. Boyd, J. Ye, and P. Zoller, Phys. Rev. Lett 101, 170504 (2008)], which involved independent lattices for different electronic states. As in the previous case, we show how existing ideas for quantum computing with Alkali atoms such as entanglement via controlled collisions can be freed from important technical restrictions. We also provide additional details on the use of collisional losses from metastable states to perform gate operations via a lossy blockade mechanism.