Quantum Simulation

Using the principles of quantum simulation, we are interested in studying many-body systems that represent models that are difficult or impossible to solve using conventional methods.  In particular, we are interested in out-of-equilibrium phenomena and their roles in the birth, preservation, and demise of quantum mechanical correlations in these generic many-body systems.  From these lessons, we hope to guide the design and manufacture of next-generation devices that use these phenomena to our advantage.

The “many-body order” in which we are interested includes the order associated with Bose-Einstein condensation, with interaction-driven transitions in periodic lattice geometries, and with the introduction of artificial gauge fields to introduce magnetic-field or spin-orbit degrees of freedom.  We are especially interested in expanding upon the Raman-transition techniques recently developed for in the artificial gauge field community to engineer situations for long-lasting states and for implementing new kinds of order that may not be possible in other systems.

Papers

Using reinforcement learning to produce stable and high-number atom clouds

On our Quantum Simulation apparatus, we implemented a reinforcement learning agent to optimize our ultracold quantum gas production at the early stages of the cycle. We find that reinforcement learning performs better than supervised machine-learning approaches, and results in a consistent, large atom number.

Demonstration of Floquet engineered non-Abelian geometric phase for holonomic quantum computing

We experimentally demonstrate Floquet-driving to generate non-Abelian geometric phases, which opens up a new way of doing holonomic quantum computing and producing novel artificial gauge fields. With methods from the ultracold neutral-atom toolbox, we surpass hurdles in maintaining degeneracy by conventional means, and our comprehensive theoretical analysis provides insight into the system's robustness to systematic error. This new quantum-control technique can be readily implemented across a variety of quantum systems used in quantum information and simulation.


Complete arbitrary control of ultracold qutrits

We isolate and manipulate three levels in 87Rb's manifold of states to realize ultracold qutrits.  We demonstrate two approaches to arbitrary single-qutrit gates and show how a dual-tone microwave can be used to connect states and perform gate operations, even when the states are not directly coupled.


GPU-accelerated solutions of the nonlinear Schrödinger equation for simulating 2D spinor BECs

In this work, we used a graphics processing unit (GPU) to accelerate the solutions of the Gross-Pitaevskii equation (a particular flavour of the nonlinear Schrodinger equation) to find fast and efficient solutions for computing the effects on BECs subjected to artificial gauge fields.

 B. D. Smith, L. W. Cooke, and L. J. LeBlanc. 
GPU-accelerated solutions of the nonlinear Schrödinger equation for simulating 2D spinor BECs
[Journal Link][arxiv.2010:15069]

Posters and other information

Exploring the effects of artificial gauge fields in BECs using numerical Gross-Pitaevskii calculations for spinor condensates (poster by LW Cooke)