We summarize some of the recent developments in building a quantum simulator with quantum optical systems, in particular laser cooled trapped ions. Our discussion focuses on digital and open system quantum simulation as realized recently for the first time.
Trapped atomic ions are among the most advanced platforms for quantum simulation, computation, and metrology, offering long coherence times and precise, individual control over both internal and motional degrees of freedom. In this review, we present a pedagogical introduction to trapped-ion systems, covering the physics of ion trapping, qubit encodings, and laser-ion interactions. We explain how spin-dependent forces generated by light fields enable both analog and digital quantum simulations of spin and spin-boson models, as well as high-fidelity quantum logic gates. We then highlight an emerging frontier in the simulation of chemical dynamics, summarizing recent experiments that demonstrate the capability of trapped ions to simulate vibronic models and excitation-transfer processes. Finally, we outline future directions in quantum simulation and discuss open challenges in scaling up trapped-ion architectures.
Ion trap system is one of the main quantum systems to realize quantum computation and simulation. Various ion trap research groups worldwide jointly drive the continuous enrichment of ion trap structures, and develop a series of high-performance three-dimensional ion trap, two-dimensional ion trap chip, and ion traps with integrated components. The structure of ion trap is gradually developing towards miniaturization, high-optical-access and integration, and is demonstrating its outstanding ability in quantum control. Ion traps are able to trap increasingly more ions and precisely manipulate the quantum state of the system. In this review, we will summarize the evolution history of the ion trap structures in the past few decades, as well as the latest advances of trapped-ion-based quantum computation and simulation. Here we present a selection of representative examples of trap structures. We will summarize the progresses in the processing technology, robustness and versatility of ion traps, and make prospects for the realization of scalable quantum computation and simulation based on ion trap system.
The enormous experimental progress in atomic, molecular and optical (AMO) physics during the last decades allows us nowadays to isolate single, a few or even many-body ensembles of microscopic particles, and to manipulate their quantum properties at a level of precision, which still seemed unthinkable some years ago. This versatile set of tools has enabled the development of the well-established concept of engineering of many-body Hamiltonians in various physical platforms. These available tools, however, can also be harnessed to extend the scenario of Hamiltonian engineering to a more general Liouvillian setting, which in addition to coherent dynamics also includes controlled dissipation in many-body quantum systems. Here, we review recent theoretical and experimental progress in different directions along these lines, with a particular focus on physical realizations with systems of atoms and ions. This comprises digital quantum simulations in a general open system setting, as well as engineering and understanding new classes of systems far away from thermodynamic equilibrium.
Trapped ions offer long coherence times and high fidelity, programmable quantum operations, making them a promising platform for quantum simulation of condensed matter systems, quantum dynamics, and problems related to high-energy physics. We review selected developments in trapped-ion qubits and architectures and discuss quantum simulation applications that utilize these emerging capabilities. This review emphasizes developments in digital (gate-based) quantum simulations that exploit trapped-ion hardware capabilities, such as flexible qubit connectivity, selective mid-circuit measurement, and classical feedback, to simulate models with long-range interactions, explore non-unitary dynamics, compress simulations of states with limited entanglement, and reduce the circuit depths required to prepare or simulate long-range entangled states.