RQS Seminar

Hamiltonian simulation is one of the most promising applications of quantum computing. Recent experimental results suggest that continuous-time analog quantum simulation would be advantageous over gate-based digital quantum simulation in the Noisy Intermediate-Size Quantum (NISQ) machine era. However, programming such analog quantum simulators is much more challenging due to the lack of a unified interface between hardware and software, and the only few known examples are all hardware-specific.

Trapped atomic ions are a highly versatile platform for quantum simulation and computation. In this talk, I will provide a brief description of the quantum control that enables both analog and digital modes of quantum simulation on this platform before reporting on two recent results: a digital quantum simulation that measured the first out-of-time-order correlators in a thermal system, and an analog simulation of particles with exotic statistics.

Abstract: The pillars of quantum theory include entanglement and operators' failure to commute. The Page curve quantifies the bipartite entanglement of a many-body system in a random pure state. This entanglement is known to decrease if one constrains extensive observables that commute with each other (Abelian ``charges''). Non-Abelian charges, which fail to commute with each other, are of current interest in quantum information and thermodynamics.

In recent years, there have been rapid breakthroughs in quantum technologies that offer new opportunities for advancing the understanding of basic quantum phenomena; realizing novel strongly correlated systems; and enhancing applications in quantum communication, computation, and sensing. Cutting edge quantum technologies simultaneously require high fidelity quantum-limited measurements and control.

Quantum computers offer the potential to perform simulations of nuclear processes that are infeasible for classical devices.

The central philosophy of statistical mechanics and random-matrix theory of complex systems is that while individual instances are essentially intractable to simulate, the statistical properties of random ensembles obey simple universal “laws”. This same philosophy promises powerful methods for studying the dynamics of quantum information in ideal and noisy quantum circuits – for which classical description of individual circuits is expected to be generically intractable.

Near-term quantum information processors will not be capable of quantum error correction, but instead will implement algorithms using the physical native interactions of the device. These interactions can be used to implement quantum gates that are often continuously-parameterized (e.g., by rotation angles), as well as to implement analog quantum simulations that seek to explore the dynamics of a particular Hamiltonian of interest.

Analog quantum simulators have the potential to provide new insight towards naturally occurring phenomena beyond the capabilities of classical computers in the near term. Incorporating controllable dissipation as a resource enables simulation of a wider range of out-of-equilibrium processes such as chemical reactions. In this talk, I will describe an experiment where we operate a hybrid qubit-oscillator circuit quantum electrodynamics processor and use it to model nonadiabatic molecular reaction dynamics through a so-called conical intersection.