CQuIC Seminars
Quantum Logic Control of a Single Molecular Ion
Presented by Dietrich Leibfried (NIST)
An amazing level of quantum control is routinely reached in modern experiments with atoms, but similar control over molecules has been an elusive goal. A method based on quantum logic spectroscopy [1] can address this challenge for a wide class of molecular ions [2,3]. We have now realized the basic elements of this proposal. In our demonstration, we trap a calcium ion together with a calcium hydride ion (CaH + ) that is a convenient stand-in for more general molecular ions. We laser-cool the two-ion crystal to its motional ground state and then drive Raman-transitions in the molecular ion, where a transition in the molecule also deposits a single quantum of excitation in the motion of the ion pair (motional 'sidebands'). We can efficiently detect this single quantum of excitation with the calcium ion, which projects the molecule into the final state of the sideband transition, a known, pure quantum state. The molecule can be coherently manipulated after the projection, and its resulting state read out by another quantum logic state detection. We demonstrate this by driving Rabi oscillations between different rotational states [4, 5] and by entangling the molecular ion with the logic ion [6]. All transitions in the molecule are either driven by a single, far off-resonant continuous-wave laser or by a far-off-resonant frequency comb. This allows us to demonstrate quantum control and precision measurements using an apparatus that admits access to a much larger class of molecular ions.
[1] P.O. Schmidt, et al. Science 309, 749 (2005).
[2] S. Ding, S. and D. N. Matsukevich, New J. Phys. 14, 023028 (2012).
[3] D. Leibfried, New J. Phys. 14, 023029 (2012).
[4] C.-W. Chou et al., Nature 545, 203 (2017).
[5] C.-W. Chou et al., Science 367, 1458 (2020).
[6] Y. Lin et al., Nature 581, 273 (2020).
3:30 pm, Thursday, September 30, 2021
Zoom,
Individuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact the Physics Department (phone: 505-277-2616, email: physics@unm.edu) well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact the Physics front office if you need written information in an alternative format.
A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at http://physics.unm.edu/pandaweb/events/index.php