Spin squeezing of a cold atomic ensemble with the nuclear spin of one-half

TL;DR

This paper demonstrates spin squeezing in a cold ytterbium atomic ensemble with nuclear spin 1/2, achieving quantum non-demolition measurement and robust quantum state manipulation suitable for quantum information processing.

Contribution

It introduces a simple, decoherence-resistant spin system using 171Yb atoms and employs short pulses for effective quantum non-demolition measurements.

Findings

Achieved 1.8 dB spin squeezing.

Demonstrated QND measurement with cold ytterbium atoms.

System is robust against decoherence due to nuclear spin properties.

Abstract

To establish an applicable system for advanced quantum information processing between light and atoms, we have demonstrated the quantum non-demolition (QND) measurement with a collective spin of cold ytterbium atoms (171Yb), and observed 1.8 (-1.5, +2.4) dB spin squeezing. Since a 171Yb atom has only a nuclear spin of 1/2 in the ground state, the system is the simplest spin ensemble and robust against decoherence. We used very short pulses with the width of 100 ns, so the interaction time became much shorter than the decoherence time, which is important for multi-step quantum information processing.