Exploring Collective Effects for Precision Measurement
A theme of atomic physics is a continual striving to gain ever greater control over single quantum objects, starting with their internal degrees of freedom and now extending to their external degrees of freedom. Having learned to exert nearly complete control over single atoms, what is the next frontier? One direction is to now exert similar levels of control over the interactions and correlations between atoms, with examples including quantum computing with trapped ions, quantum many-body simulations in degenerate atomic gases, and the deterministic assembly of molecules. Our lab has been asking the question: is it also possible to exploit atom-atom correlations and entanglement to advance the field of precision measurement beyond the independent-atom paradigm? We have explored this question along two fronts that will be discussed: a superradiant laser that operates with <1photon on average inside the laser cavity, and surpassing the standard quantum limit on phase estimation by a factor of 10. Possible future applications include robust millihertz linewidth optical lasers and advanced optical lattice clocks.