2007/05/06 by C. F. Roos, Thomas Monz, T. Monz +8 · 2 citations
Computer Science · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum Information and Cryptography #Quantum optics and atomic interactions #quant-ph
paper · pdf · doi:10.1103/physreva.77.040302
published as Phys. Rev. A 77, 040302(R) (2008)
arxiv created 2007/05/06 · openalex publication_date 2008/04/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We experimentally investigate nonlinear couplings between individual quanta of the vibrational modes of strings of cold ions stored in linear ion traps. The nonlinearity is caused by the ions' Coulomb interaction and gives rise to a Kerr-type interaction Hamiltonian H=\ensuremathℏ\ensuremathχ\stackrel\ifmmode \else \\finr\stackrel\ifmmode \else \\fins, where \stackrel\ifmmode \else \\finr, \stackrel\ifmmode \else \\fins are phonon number operators of two interacting vibrational modes. We precisely measure the resulting oscillation frequency shift and observe a collapse and revival of the contrast in a Ramsey experiment over a range of trap frequencies. With 2.97\phantom\rule0.3em0exMHz stretch mode and 3.61\phantom\rule0.3em0exMHz rocking mode frequencies, we observed a coupling of 20.5\phantom\rule0.3em0exHz∕phonon. Implications for ion trap experiments aiming at high-fidelity quantum gate operations are discussed.