Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non‐equilibrium phenomena in atom traps: quantum emulation of ultrafast atom‐light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly‐driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid‐state experiments, facilitating a complementary approach to open problems in non‐equilibrium condensed matter.
Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non‐equilibrium phenomena in atom traps: quantum emulation of ultrafast atom‐light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly‐driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid‐state experiments, facilitating a complementary approach to open problems in non‐equilibrium condensed matter.
Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non‐equilibrium phenomena in atom traps: quantum emulation of ultrafast atom‐light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly‐driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid‐state experiments, facilitating a complementary approach to open problems in non‐equilibrium condensed matter.
Quantum emulation of extreme non-equilibrium phenomena is a natural application of the precision and control of ultracold atomic physics experiments. In particular, ``Floquet engineering" with an explicitly time-dependent Hamiltonian enables the creation of states of matter that can only exist in the presence of strong driving. In this work, we create and study such tunable strongly driven quantum systems. We use quantum degenerate lithium as a platform because of its light mass, fast tunneling rates, and broadly tunable Feshbach resonance, which allow the study of a wide variety of systems: noninteracting Bosons, strongly interacting many body systems, and bright solitons, to name a few. We describe the experimental setup used to create a 7Li Bose-Einstein condensate as an archetypal quantum platform, and then discuss three key results: the first direct measurement of position-space Bloch oscillations in a cold atom system, the creation of a massive relativistic harmonic oscillator, and finally the demonstration of a new method for controlled long-range quantum coherent transport enabled by Floquet band engineering.
We demonstrate a physical quantum simulator of ultrafast phenomena, in which
time-varying forces on neutral atoms in a tunable optical trap emulate the
electric fields of a pulsed laser acting on electrons or nuclei in a binding
potential. The simulator operates in regimes equivalent to those of ultrafast
and strong-field pulsed-laser experiments, opening up a hitherto unexplored
application of quantum simulation techniques and a complementary path towards
investigating open questions in ultrafast science. Counter-intuitively, this
approach emulates some of the fastest processes in atomic physics with some of
the slowest, giving rise to a temporal magnification factor of up to twelve
orders of magnitude which greatly simplifies experimental access to the
dynamics. The correspondence with ultrafast science is demonstrated by a
sequence of experiments: we perform nonlinear spectroscopy of a many-body bound
state, control the excitation spectrum by shaping the potential, observe
sub-cycle unbinding dynamics during strong few-cycle pulses, and directly
measure carrier-envelope phase dependence of the response to an
ultrafast-equivalent pulse.
Quantum hardware platforms are getting increasingly sophisticated in their ability to simulate condensed matter, including but not limited to strongly-correlated, topological, and non-equilibrium phenomena. This review surveys recent progress in quantum-hardware-based simulations of condensed matter, primarily emphasizing gate-based digital quantum computer simulation, with analog experiments discussed as complementary benchmarks. We first review major hardware platforms, including superconducting qubits, trapped-ions, ultracold atoms, Rydberg arrays, photonic systems, and moire quantum materials. We then introduce the basic ingredients of digital quantum simulation. Building on this foundation, we discuss representative applications to condensed-matter physics, spanning ground-state problems, strongly correlated matter, topological phases, non-equilibrium dynamics, open-system physics, and high-energy-physics-inspired simulations. Finally, we summarize key methodological tools used in state-of-the-art quantum-simulation workflows. We emphasize that present noisy quantum simulations serve not only as near-term demonstrations, but also as prototypes for the encodings, diagnostic protocols and error-control strategies required for future fault-tolerant quantum simulation.
Ultracold quantum gases offer a versatile platform to study a wide range of open questions in condensed matter physics and beyond. In particular, their controllability, isolation from noisy thermal environments, and evolution on experimentally-accessible timescales make them a natural choice to probe the effects of driving on time evolution and energy. This thesis details the construction of two cold-atom apparatuses, a lithium machine and a strontium machine, for quantum emulation experiments studying driven systems. Initial numerical simulations along two experimental lines are briefly discussed, and results from the first two experiments on the strontium machine are then presented. In the first, a strontium Bose-Einstein condensate in an optical trap is strongly driven to emulate ultrafast photoionization processes; in a series of proof-of-principle experiments measuring the momenta and energy of particles ejected from the trap, we demonstrate the viability of this technique to study open questions in strong-field physics. The second experiment realizes a tunable quasicrystal, the energy structure for which is described by the multifractal Hofstadter butterfly. Quasiperiodic structures host not only phonons, but also a higher-dimension analogue called phasons. In the experiment, we demonstrate phasonic spectroscopy for the first time by directly driving one of these modes; we characterize the coupling to the resulting excitations, and directly map a slice of the Hofstadter energy spectrum.
Abstract Ultrafast electronic dynamics are typically studied using pulsed lasers. Here we demonstrate a complementary experimental approach: quantum simulation of ultrafast dynamics using trapped ultracold atoms. Counter-intuitively, this technique emulates some of the fastest processes in atomic physics with some of the slowest, leading to a temporal magnification factor of up to 12 orders of magnitude. In these experiments, time-varying forces on neutral atoms in the ground state of a tunable optical trap emulate the electric fields of a pulsed laser acting on bound charged particles. We demonstrate the correspondence with ultrafast science by a sequence of experiments: nonlinear spectroscopy of a many-body bound state, control of the excitation spectrum by potential shaping, observation of sub-cycle unbinding dynamics during strong few-cycle pulses, and direct measurement of carrier-envelope phase dependence of the response to an ultrafast-equivalent pulse. These results establish cold-atom quantum simulation as a complementary tool for studying ultrafast dynamics.