Khan W. Mahmud

Dynamically decoupled three-body interactions with applications to interaction-based quantum metrology

We propose a stroboscopic method to dynamically decouple the effects of two-body atom-atom interactions for ultracold atoms, and realize a system dominated by elastic three-body interactions. Using this method, we show that it is possible to achieve the optimal scaling behavior predicted for interaction-based quantum metrology with three-body interactions. Specifically, we show that for ultracold atoms quenched in an optical lattice, we can measure the three-body interaction strength with a precision proportional to

Collapse and revivals for systems of short-range phase coherence

{\bar n}^{-5/2}

Dynamics of spin-1 bosons in an optical lattice: Spin mixing, quantum-phase-revival spectroscopy, and effective three-body interactions

using homodyne quadrature interferometry, and

Spin-Orbit Coupled Bosons in One Dimension: Emergent Gauge Field and Lifshitz Transition

{\bar n}^{-7/4}

Phase transitions and emergent gauge potentials in strongly interacting spin-orbit coupled bosons

using conventional collapse-and-revival techniques, where

Driven-dissipative bosons in open boundary and inhomogeneous cavity arrays

{\bar n}

Bloch oscillations collapse and revival of interacting bosons in an optical lattice

is the mean number of atoms per lattice site. Both precision scalings surpass the nonlinear scaling of

Bloch oscillations and quench dynamics of interacting bosons in an optical lattice

{\bar n}^{-3/2}

Particle-hole pair excitations in Mott insulator quench dynamics

, the best so far achieved or proposed with a physical system. Our method of achieving a decoupled three-body interacting system may also have applications in the creation of exotic three-body states and phases.

Nonlinear interferometric scaling from spinor atom density measurements

We predict the existence of novel collapse and revival oscillations that are a distinctive signature of the short-range off-diagonal coherence associated with particle-hole pairs in Mott insulator states. Starting with an atomic Mott state in a one-dimensional optical lattice, suddenly raising the lattice depth freezes the particle-hole pairs in place and induces phase oscillations. The peak of the quasi-momentum distribution, revealed through time of flight interference, oscillates between a maximum occupation at zero quasi-momentum (the