Lin, Yiheng

Monday Nov 18, 2013
Time: 10:45
Place: ETH Science City, HPF G 6
Host: Jonathan Home

Dissipative production of a maximally entangled steady state

Yiheng Lin
National Institute of Standards and Technology, Boulder, Colorado, USA

We combine unitary processes with engineered dissipation into a zero-temperature bath to deterministically produce and stabilize an approximate Bell state of two trapped-ion qubits independent of their initial state [arXiv:1307.4443]. We implement the process on a ⁹Be⁺-²⁴Mg⁺-²⁴Mg⁺-⁹Be⁺ four-ion chain in a linear radio-frequency Paul trap. The two ⁹Be⁺ ions serve as qubit ions while the two ²⁴Mg⁺ ions are used for sympathetic cooling as the zero-temperature bath. We simultaneously apply a combination of a unitary process consists of microwave and laser fields on ⁹Be⁺ ions, and dissipative processes of optical pumping on ⁹Be⁺ ions and sympathetic cooling on ²⁴Mg⁺ ions. We realize maximally entangled steady states with a fidelity of F = 0.75(3). We also demonstrate that a sequential stepwise application of unitary and dissipative process can speed up the dynamics of the scheme and achieve a fidelity of F = 0.89(2) after approximately 30 repetitions. In both cases, the errors can be attributed to known experimental imperfections.

Acknowledgements: This work was supported by IARPA through ARO (Grant No. DNI-11523A1), ONR, the NIST Quantum Information Program, the European Union’s Seventh Framework Program through SIQS (grant no. 600645) and through the ERC grant QIOS (grant no. 306576).

Co-Authors:  J. P. Gaebler,  T. R. Tan, R. Bowler, D. Leibfried, and D. J. Wineland, National Institute of Standards and Technology, Boulder, USA
F. Reiter, A. S. Sørensen, QUANTOP, The Niels Bohr Institute, University of Copenhagen, Denmark