Spin squeezing in optical lattice clocks via lattice-based QND measurements
Final Report Abstract
In the near future, the precision of state-of-the art optical atomic clocks will be limited by fundamental noise sources rather than technical noise. Overcoming these precision limits requires control over quantum effects. In the research project covered by this report we have contributed to that goal by studying a coupled atom-cavity system. In contrast to systems that have been studied previously in cavity quantum electrondynamics (QED) the atoms considered here have a transition linewidth that is about ten orders of magnitude narrower. As a consequence, coherences of that transtition are much more long lived and at the same time the coupling to the cavity mode is about five orders of magnitude weaker. The main contribution of this research project is a detailed analysis of measurements of atomic properties using the lattice beams that generate the potential in which the atoms are trapped. The information contained in these fields is normally unused but, as we show, can be exploited to gather information about the atomic state. In particular we have shown that the lattice beams can be used to measure the populations of the two clock states of the atoms. These populations can be measured with resolution that is better than the standard quantum limit, thus enabling squeezing of the atomic pseudo spin. Spin squeezing can reduce the projection noise and thus enable more stable atomic clocks. In addition to the internal state of the atoms, we have also investigated whether the center of mass state of the atoms can be determined with the lattice beams. We have shown that the lattice beams can be used for high resolution measurements of Bloch oscillations that the atoms undergo in a constant force field such as gravity. By measuring the frequency of these oscillations it is possible to infer the strength of gravity. We have explored novel methods of light generation that are based on the cavity QED systems studied in the previous two parts of the project. The idea is to exploit collective emission from an ensemble of atoms with an ultra-narrow transition, instead of stimulated emission as in a laser. The light source based on that approach has the potential to have a phase stability that is two orders of magnitude better than the current state-of-the art. A light source with such an exceptional phase stability could enable correspondingly better atomic clocks.
Publications
- “Spin squeezing in optical lattice clocks via lattice-based QND measurements”, New J. Phys. 10, 073014 (2008)
D. Meiser, Jun Ye, and M. J. Holland
- “Cavity QED with very weak dipoles: Prospects for a mHz-linewidth laser”, Institute of Applied Physics, University of Bonn, Germany, May 12, 2009
D. Meiser, Jun Ye, J. K. Thompson, and M. J. Holland
- “Cavity QED with very weak dipoles: Prospects for a mHz-linewidth laser”, Physikalisch Technische Bundesanstalt, Germany, May 13, 2009
D. Meiser, Jun Ye, J. K. Thompson, and M. J. Holland
- “Cavity QED with very weak dipoles: Prospects for a mHz-linewidth laser”, University of Innsbruck, Austria, May 5, 2009
D. Meiser, Jun Ye, J. K. Thompson, and M. J. Holland
- “Cavity QED with very weak dipoles: Prospects for a mHz-linewidth laser”, University of Stuttgart, Germany, May 11, 2009
D. Meiser, Jun Ye, J. K. Thompson, and M. J. Holland
- “Combining lattice clocks with cavity QED: Prospects for a mHz-linewidth laser”, DAMOP 2009, Charlottesville, Virginia, USA
D. Meiser, Jun Ye, and M. J. Holland
- “Nondestructive cavity QED probe of Bloch oscillations in a gas of ultracold atoms”, Phys Rev. A 80, 043803 (2009)
B. M. Peden, D. Meiser, M. L. Chiofalo, and M. J. Holland
- “Prospects for a Millihertz-Linewidth Laser”, Phys Rev. Lett. 102, 163601 (2009)
D. Meiser, Jun Ye, D.R. Carlson, and M. J. Holland
- “Robustness of Heisenberg-limited interferometry with balanced Fock states”, New J. Phys. 11, 033002 (2009)
D. Meiser and M. J. Holland
