Quantum Simulation
Quantum simulation of a $\mathrm{U}(1)$ lattice gauge theory on a Bose–Hubbard system;
Nature 587, 392–396 (2020)
Many-particle quantum systems challenge us with a large number of fundamental open questions, such as the mechanisms behind high-temperature superconductivity or quark confinement. One obstacle for developing a full theoretical understanding of quantum many-body systems is the difficulty of solving them on classical computers, as the required computing resources grow exponentially with the number of constituents. In 1982, Feynman proposed an alternative approach to tackle such problems, namely to encode them in specifically engineered experimental systems that themselves are governed by the laws of quantum mechanics, a concept now termed “quantum simulation”. With their high degree of precision and controllability, current experimental platforms such as cold atomic gases, trapped ions, or superconducting qubits, are perfectly suited for this purpose.
In this project, we aim at identifying difficult problems and interesting phenomena that are worthy targets of quantum simulations, and to develop schemes to realize them in realistic experiments. Currently, we are especially interested in quantum transport and thermalization, strongly-correlated systems, topological phases of matter, and lattice gauge theories. We are also addressing a crucial challenge for the further development of the field, namely how to ensure the reliability of quantum simulators once they explore regimes where benchmarks with classical computers are no longer possible.
Philipp Hauke
Professor
Soumik Bandyopadhyay
Postdoc
Andrea Legramandi
Postdoc
Emanuele Tirrito
Postdoc
Now Postdoctoral Researcher at ICTP Triste, Italy
Julius Mildenberger
Postdoc
Alberto Bottarelli
PhD Student
Matteo M. Wauters
Postdoc
Alex Windey
PhD Student
David Pascual Solis
PhD Student
Chiara Capecci
Postdoc
Naga Dileep Varikuti
Postdoc
Publications
Quantifying non-Hermiticity using single- and many-particle quantum properties
The non-Hermitian paradigm of quantum systems displays salient features drastically different from Hermitian counterparts. In this …
Miscibility-immiscibility transition of strongly interacting bosonic mixtures in optical lattices
Interaction plays key role in the mixing properties of a multi-component system. The miscibility-immiscibility transition (MIT) in a …
Unraveling the emergence of quantum state designs in systems with symmetry
Quantum state designs, by enabling an efficient sampling of random quantum states, play a quintessential role in devising and …
Beyond braid statistics: Constructing a lattice model for anyons with exchange statistics intrinsic to one dimension
Anyons obeying fractional exchange statistics arise naturally in two dimensions: Hard-core two-body constraints make the configuration …
Variational quantum simulation of U(1) lattice gauge theories with qudit systems
Lattice gauge theories are fundamental to various fields, including particle physics, condensed matter, and quantum information theory. …
Observation of microscopic confinement dynamics by a tunable topological $\theta$-angle
The topological $\theta$-angle is central to the understanding of a plethora of phenomena in condensed matter and high-energy physics …
Many-body magic via Pauli–Markov chains — from criticality to gauge theories
We introduce a method to measure many-body magic in quantum systems based on a statistical exploration of Pauli strings via Markov …
Spin-$S$ $U(1)$ Quantum Link Models with Dynamical Matter on a Quantum Simulator
Quantum link models (QLMs) offer the realistic prospect for the practical implementation of lattice quantum electrodynamics (QED) on …
A cavity quantum electrodynamics implementation of the Sachdev--Ye--Kitaev model
The search for a quantum theory of gravity has led to the discovery of quantum many-body systems that are dual to gravitational models …
Dynamical quantum phase transitions in spin-$S$ $U(1)$ quantum link models
Dynamical quantum phase transitions (DQPTs) are a powerful concept of probing far-from-equilibrium criticality in quantum many-body …
Absence of operator growth for average equal-time observables in charge-conserved sectors of the Sachdev-Ye-Kitaev model
Quantum scrambling plays an important role in understanding thermalization in closed quantum systems. By this effect, quantum …
Engineering random spin models with atoms in a high-finesse cavity
All-to-all interacting, disordered quantum many-body models have a wide range of applications across disciplines, from spin glasses in …
Quantum Hall and Synthetic Magnetic-Field Effects in Ultra-Cold Atomic Systems
In this Chapter, we give a brief review of the state of the art of theoretical and experimental studies of synthetic magnetic fields …
Stabilizing Gauge Theories in Quantum Simulators: A Brief Review
Quantum simulation is at the heart of the ongoing ‘‘second’’ quantum revolution, with various synthetic quantum …
Tuning the Topological $\theta$-Angle in Cold-Atom Quantum Simulators of Gauge Theories
The topological $\theta$-angle in gauge theories engenders a series of fundamental phenomena, including violations of charge-parity …
Probing confinement in a $\mathbb{Z}_2$ lattice gauge theory on a quantum computer
Digital quantum simulators provide a table-top platform for addressing salient questions in particle and condensed-matter physics. A …
Robust quantum many-body scars in lattice gauge theories
Quantum many-body scarring is a paradigm of weak ergodicity breaking arising due to the presence of special nonthermal many-body …
Disorder-free localization with Stark gauge protection
Disorder-free localization in translation-invariant gauge theories presents a counterintuitive yet powerful framework of ergodicity …
Achieving the quantum field theory limit in far-from-equilibrium quantum link models
Realizations of gauge theories in setups of quantum synthetic matter open up the possibility of probing salient exotic phenomena in …
Ground-state phase diagram of quantum link electrodynamics in $(2+1)$-d
The exploration of phase diagrams of strongly interacting gauge theories coupled to matter in lower dimensions promises the …
Enhancing disorder-free localization through dynamically emergent local symmetries
Disorder-free localization is a recently discovered phenomenon of nonergodicity that can emerge in quantum many-body systems hosting …
Stabilizing Disorder-Free Localization
Disorder-free localization is a paradigm of nonergodicity in translation-invariant quantum many-body systems hosting gauge symmetries. …
Suppressing nonperturbative gauge errors in the thermodynamic limit using local pseudogenerators
With recent progress in quantum simulations of lattice-gauge theories, it is becoming a pressing question how to reliably protect the …
Stabilizing lattice gauge theories through simplified local pseudo generators
The postulate of gauge invariance in nature does not lend itself directly to implementations of lattice gauge theories in modern setups …
Universal equilibration dynamics of the Sachdev-Ye-Kitaev model
Equilibrium quantum many-body systems in the vicinity of phase transitions generically manifest universality. In contrast, limited …
Engineering a $\mathrm{U}(1)$ lattice gauge theory in classical electric circuits
Lattice gauge theories are fundamental to such distinct fields as particle physics, condensed matter, and quantum information science. …
Thermalization dynamics of a gauge theory on a quantum simulator
Gauge theories form the foundation of modern physics, with applications ranging from elementary particle physics and early-universe …
Gauge protection in non-Abelian lattice gauge theories
Protection of gauge invariance in experimental realizations of lattice gauge theories based on energy-penalty schemes has recently …
Dynamical phase transitions in quantum spin models with antiferromagnetic long-range interactions
In recent years, dynamical phase transitions and out-of-equilibrium criticality have been at the forefront of ultracold gases and …
Generalized Discrete Truncated Wigner Approximation for Nonadiabtic Quantum-Classical Dynamics
Nonadiabatic molecular dynamics occur in a wide range of chemical reactions and femtochemistry experiments involving electronically …
Reliability of lattice gauge theories in the thermodynamic limit
Although gauge invariance is a postulate in fundamental theories of nature such as quantum electrodynamics, in quantum-simulation …
Towards the continuum limit of a $(1+1)$d quantum link Schwinger model
The solution of gauge theories is one of the most promising applications of quantum technologies. Here, we discuss the approach to the …
Gauge-Symmetry Violation Quantum Phase Transition in Lattice Gauge Theories
Gauge symmetry plays a key role in our description of subatomic matter. The vanishing photon mass, the long-ranged Coulomb law, and …
Diffusive-to-ballistic crossover of symmetry violation in open many-body systems
Conservation laws in a quantum many-body system play a direct role in its dynamic behavior. Understanding the effect of weakly breaking …
Fate of Lattice Gauge Theories Under Decoherence
A major test of the capabilities of modern quantum simulators and NISQ devices is the reliable realization of gauge theories, which …
Analog cosmological reheating in an ultracold Bose gas
Cosmological reheating describes the transition of the post-inflationary universe to a hot and thermal state. In order to shed light on …
Gauge-Symmetry Protection Using Single-Body Terms
Quantum-simulator hardware promises new insights into problems from particle and nuclear physics. A major challenge is to reproduce …
Robustness of gauge-invariant dynamics against defects in ultracold-atom gauge theories
Recent years have seen strong progress in quantum simulation of gauge-theory dynamics using ultracold-atom experiments. A principal …
Origin of staircase prethermalization in lattice gauge theories
Quantum many-body systems with exact local gauge symmetries exhibit rich out-of-equilibrium physics such as constrained dynamics and …
Staircase prethermalization and constrained dynamics in lattice gauge theories
The dynamics of lattice gauge theories is characterized by an abundance of local symmetry constraints. Although errors that break gauge …
Observation of gauge invariance in a 71-site quantum simulator
The modern description of elementary particles is built on gauge theories. Such theories implement fundamental laws of physics by local …
Reliability of lattice gauge theories
Currently, there are intense experimental efforts to realize lattice gauge theories in quantum simulators. Except for specific models, …
A scalable realization of local U(1) gauge invariance in cold atomic mixtures
In the fundamental laws of physics, gauge fields mediate the interaction between charged particles. An example is quantum …
Many-body localization in a quantum simulator with programmable random disorder
When a system thermalizes it loses all memory of its initialconditions. Even within a closed quantum system, subsystemsusually …
Can one trust quantum simulators?
Various fundamental phenomena of strongly correlated quantum systems such as high-$T_c$ superconductivity, the fractional quantum-Hall …
Talks
A quantum simulation scheme and equilibration/thermalization physics of the Sachdev-Ye-Kitaev (SYK) model
The quest for a quantum theory of gravity has led to the discovery of quantum many-body systems that are dual to gravitational models …
Implementing a $\mathbb{Z}_2$ Lattice Gauge Theory in a Digital Quantum Simulator
Digital quantum simulators provide a table-top platform for addressing salient questions in particle, nuclear, and condensed-matter …
Analog quantum simulation and universal dynamics of the Sachdev-Ye-Kitaev model
Universal dynamics of Sachdev-Ye-Kitaev model
The Sachdev-Ye-Kitaev (SYK) model was introduced in the context of explaining the properties of “strange metals,” and has been found to …
Quantum Simulating Lattice Gauge Theories — High-Energy Physics at Ultra-Cold Temperatures
Gauge theories are at the heart of our modern understanding of physics, but solving their out-of-equilibrium dynamics is extremely …
Staircase Prethermalization and Constrained Dynamics in Lattice Gauge Theories
The dynamics of lattice gauge theories is characterized by an abundance of local symmetry constraints. Although errors that break gauge …