A5049062960- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Theoretical and Computational Physics
- Opinion Dynamics and Social Influence
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Metamaterials and Metasurfaces Applications
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Antenna and Metasurface Technologies
- Neural Networks and Reservoir Computing
- Quantum Mechanics and Applications
- Quantum Chromodynamics and Particle Interactions
- Advanced Condensed Matter Physics
- Quantum chaos and dynamical systems
- Complex Systems and Time Series Analysis
- Topological Materials and Phenomena
- Spectroscopy and Quantum Chemical Studies
- Orbital Angular Momentum in Optics
- Advanced Optical Imaging Technologies
- Electronic and Structural Properties of Oxides
- Model Reduction and Neural Networks
Ludwig-Maximilians-Universität München
2013-2025
Munich Center for Quantum Science and Technology
2022-2025
University of Trento
2020-2025
Max Planck Institute of Quantum Optics
2010-2025
Freie Universität Berlin
2024-2025
University of Leeds
2023
Technical University of Munich
2018-2022
Max Planck Institute for the Physics of Complex Systems
2017-2022
Heidelberg Institute for Theoretical Studies
2020-2021
Heidelberg University
2020-2021
Using an infinite Matrix Product State (iMPS) technique based on the time-dependent variational principle (TDVP), we study two major types of dynamical phase transitions (DPT) in one-dimensional transverse-field Ising model (TFIM) with long-range power-law ($\propto1/r^{\alpha}$ $r$ inter-spin distance) interactions out equilibrium thermodynamic limit -- \textit{DPT-I}: order parameter a (quasi-)steady state, and \textit{DPT-II}: non-analyticities (cusps) Loschmidt-echo return rate. We...
Gauge theories form the foundation of modern physics, with applications ranging from elementary particle physics and early-universe cosmology to condensed matter systems. We perform quantum simulations unitary dynamics a U(1) symmetric gauge field theory demonstrate emergent irreversible behavior. The highly constrained are encoded in one-dimensional Bose-Hubbard simulator, which couples fermionic fields through dynamical fields. investigated global quenches equilibration steady state well...
The ongoing quest for understanding nonequilibrium dynamics of complex quantum systems underpins the foundation statistical physics as well development technology. Quantum many-body scarring has recently opened a window into novel mechanisms delaying onset thermalization by preparing system in special initial states, such $\mathbb{Z}_2$ state Rydberg atom system. Here we realize Bose-Hubbard simulator from previously unknown conditions unit-filling state. We develop quantum-interference...
As a paradigm of weak ergodicity breaking in disorder-free nonintegrable models, quantum many-body scars (QMBS) can offer deep insights into the thermalization dynamics gauge theories. Having been first discovered spin-$1/2$ link formulation Schwinger model, it is fundamental question as to whether QMBS persist for $S>1/2$ since such theories converge lattice model large-$S$ limit, which appropriate version QED one spatial dimension. In this work, we address by exploring spin-$S$...
The high level of control and precision achievable in current synthetic quantum matter setups has enabled first attempts at quantum-simulating various intriguing phenomena condensed physics, including those probing thermalization or its absence closed systems. In a recent work [Desaules \textit{et al.} [arXiv:2203.08830], we have shown that many-body scars -- special low-entropy eigenstates weakly break ergodicity nonintegrable systems arise spin-$S$ link models converge to $(1+1)-$D lattice...
Quantum computers offer an intriguing path for a paradigmatic change of computing in the natural sciences and beyond, with potential achieving so-called quantum advantage—namely, significant (in some cases exponential) speedup numerical simulations. The rapid development hardware devices various realizations qubits enables execution small-scale but representative applications on computers. In particular, high-energy physics community plays pivotal role accessing power computing, since field...
The existence or absence of nonanalytic cusps in the Loschmidt-echo return rate is traditionally employed to distinguish between a regular dynamical phase (regular cusps) and trivial (no quantum spin chains after global quench. However, numerical evidence recent study (J. C. Halimeh V. Zauner-Stauber, arXiv:1610.02019) suggests that instead phase, distinct anomalous characterized by novel type occurs one-dimensional transverse-field Ising model when interactions are sufficiently long range....
We numerically study the dynamics after a parameter quench in one-dimensional transverse-field Ising model with long-range interactions ($\propto 1/r^\alpha$ distance $r$), for finite chains and also directly thermodynamic limit. In nonequilibrium, i.e., before system settles into thermal state, we find long-lived regime that is characterized by prethermal value of magnetization, which general differs from its value. ferromagnetic phase stabilized dynamically: as function parameter,...
The Loschmidt echo (LE) is a purely quantum-mechanical quantity whose determination for large quantum many-body systems requires an exceptionally precise knowledge of all eigenstates and eigenenergies. One might therefore be tempted to dismiss the applicability any approximations underlying time evolution as hopeless. However, using fully connected transverse-field Ising model (FC-TFIM) example, we show that this indeed not case, simple semiclassical approximation well described by...
We construct the finite-temperature dynamical phase diagram of fully connected transverse-field Ising model from vantage point two disparate concepts criticality. An analytical derivation classical dynamics and exact diagonalization simulations are used to study after a quantum quench in system prepared thermal equilibrium state. The different phases characterized by type nonanalyticities that emerge an appropriately defined Loschmidt-echo return rate directly correspond determined...
Quantum-simulator hardware promises new insights into problems from particle and nuclear physics. A major challenge is to reproduce gauge invariance, as violations of this quintessential property lattice theories can have dramatic consequences, e.g., the generation a photon mass in quantum electrodynamics. Here, we introduce an experimentally friendly method protect invariance $\mathrm{U}(1)$ against coherent errors controllable way. Our employs only single-body energy-penalty terms, thus...
Currently, there are intense experimental efforts to realize lattice gauge theories in quantum simulators. Except for specific models, however, practical simulators can never be fine-tuned perfect local invariance. There is thus a strong need rigorous understanding of gauge-invariance violation and how reliably protect against it. As we show through analytic numerical evidence, the presence invariance-breaking term accumulates only perturbatively at short times before proliferating very long...
We investigate two separate notions of dynamical phase transitions in the two-dimensional nearest-neighbor transverse-field Ising model on a square lattice using matrix product states and hybrid infinite time-evolving block decimation algorithm, where is implemented an infinitely long cylinder with finite diameter along which periodic boundary conditions are employed. Starting ordered initial state, our numerical results suggest that quenches below critical point give rise to ferromagnetic...
Protection of gauge invariance in experimental realizations lattice theories based on energy-penalty schemes has recently stimulated impressive efforts both theoretically and setups quantum synthetic matter. A major challenge is the reliability such non-Abelian where local conservation laws do not commute. Here, we show through exact diagonalization that can be reliably controlled using gauge-protection terms energetically stabilize target sector Hilbert space, suppressing violations due to...
Gauge fields coupled to dynamical matter are ubiquitous in many disciplines of physics, ranging from particle condensed but their implementation large-scale quantum simulators remains challenging. Here we propose a realistic scheme for Rydberg atom array experiments which $\mathbb{Z}_2$ gauge structure with charges emerges on experimentally relevant timescales only local two-body interactions and one-body terms two spatial dimensions. The enables the experimental study variety models,...
Quantum many-body scarring is a paradigm of weak ergodicity breaking arising due to the presence special nonthermal eigenstates that possess low entanglement entropy, are equally spaced in energy, and concentrate certain parts Hilbert space. Though scars have been shown be intimately connected gauge theories, their stability such experimentally relevant models still an open question, it generally considered they exist only under fine-tuned conditions. In this work, we show through...
Quantum computers offer an intriguing path for a paradigmatic change of computing in the natural sciences and beyond, with potential achieving so-called quantum advantage, namely significant (in some cases exponential) speed-up numerical simulations. The rapid development hardware devices various realizations qubits enables execution small scale but representative applications on computers. In particular, high-energy physics community plays pivotal role accessing power computing, since field...
Using the framework of infinite matrix product states, existence an anomalous dynamical phase for transverse-field Ising chain with sufficiently long-range interactions was first reported in J. C. Halimeh and V. Zauner-Stauber [Phys. Rev. B 96, 134427 (2017)], where it shown that cusps arise Loschmidt-echo return rate small quenches within ferromagnetic phase. In this work we further probe nature through calculating corresponding Fisher-zero lines complex time plane. We find these exhibit a...
Within the ultimate goal of classifying universality in quantum many-body dynamics, understanding relation between out-of-equilibrium and equilibrium criticality is a crucial objective. Models with power-law interactions exhibit rich well-understood critical behavior equilibrium, but picture has remained incomplete, despite recent experimental progress. We construct dynamical phase diagram free-fermionic chains hopping pairing provide analytic numerical evidence showing direct connection...
This paper establishes a direct connection between the equilibrium quasiparticle spectrum of model and nonanalytic behavior appearing in its Loschmidt return rate. For small quenches within ordered phase, form so-called anomalous cusps occurs rate only when lowest-lying quasiparticles are local excitations.
The topological $\theta$-angle in gauge theories engenders a series of fundamental phenomena, including violations charge-parity (CP) symmetry, dynamical transitions, and confinement--deconfinement transitions. At the same time, it poses major challenges for theoretical studies, as implies sign problem numerical simulations. Analog quantum simulators open promising prospect treating many-body systems with such terms, but, contrary to their digital counterparts, they have not yet demonstrated...
The postulate of gauge invariance in nature does not lend itself directly to implementations lattice theories modern setups quantum synthetic matter. Unavoidable gauge-breaking errors such devices require be enforced for faithful simulation gauge-theory physics. This poses major experimental challenges, large part due the complexity gauge-symmetry generators. Here, we show that can reliably stabilized by employing simplified \textit{local pseudogenerators} designed within physical sector...