Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Emergent black hole dynamics in critical Floquet systems

Bastien Lapierre, Kenny Choo, Clément Tauber, Apoorv Tiwari, Titus Neupert, R. Chitra

Published Jan 1, 2020• 64 citations
Publisher

Abstract

While driven interacting quantum matter is generically subject to heating and scrambling, certain classes of systems evade this paradigm. We study such an exceptional class in periodically driven critical (1+1)-dimensional systems with a spatially modulated but disorder-free time evolution operator. Instead of complete scrambling, the excitations of the system remain well defined. Their propagation is analogous to the evolution along light cones in a curved spacetime obtained by two black holes. The Hawking temperature serves as an order parameter which distinguishes between heating and nonheating phases. Beyond a timescale determined by the inverse Hawking temperature, excitations are absorbed by the black holes resulting in a singular concentration of energy at their horizon. We obtain these results analytically within conformal field theory, capitalizing on a mapping to sine-squared deformed field theories. Furthermore, by means of numerical calculations for an interacting XXZ spin-12 chain, we demonstrate that our findings survive lattice regularization.

DOI
10.3929/ethz-b-000458637

Related papers

Emergent black hole dynamics in critical Floquet systems

Bastien Lapierre, Kenny Choo, Clément Tauber +3 more

In this paper the authors study a one-dimensional quantum chain subject to a periodic drive that alternates between two coupling profiles modulated in space. They discover the existence of a heating phase where all the excitations accumulate periodically at two specific points of the chain dubbed horizons, through an exact analogy with the ones from black holes. The system heats up by endlessly absorbing the energy of the drive in a non-homogeneous way along the two horizons.

arXiv:1909.08618•Physical Review Research•Apr 27, 2020•61 citations

Thermal and dissipative effects on the heating transition in a driven critical system

Kenny Choo, Bastien Lapierre, Clemens Kuhlenkamp +3 more

We study the dissipative dynamics of a periodically driven inhomogeneous critical lattice model in one dimension. The closed system dynamics starting from pure initial states is well-described by a driven Conformal Field Theory (CFT), which predicts the existence of both heating and non-heating phases in such systems. Heating is inhomogeneous and is manifested via the emergence of black-hole like horizons in the system. The robustness of this CFT phenomenology when considering thermal initial states and open systems remains elusive. First, we present analytical results for the Floquet CFT time evolution for thermal initial states. Moreover, using exact calculations of the time evolution of the lattice density matrix, we demonstrate that for short and intermediate times, the closed system phase diagram comprising heating and non-heating phases, persists for thermal initial states on the lattice. Secondly, in the fully open system with boundary dissipators, we show that the nontrivial spatial structure of the heating phase survives particle-conserving and non-conserving dissipations through clear signatures in mutual information and energy density evolution.

arXiv:2205.02869•SciPost Physics•Nov 4, 2022•14 citations

Floquet engineered inhomogeneous quantum chaos in critical systems

Bastien Lapierre, Tokiro Numasawa, Titus Neupert +1 more

We study universal chaotic dynamics of a large class of periodically driven critical systems described by spatially inhomogeneous conformal field theories. By employing an effective curved spacetime approach, we show that the onset of quantum chaotic correlations, captured by the Lyapunov exponent of out-of-time-order correlators (OTOCs), is set by the Hawking temperature of emergent Floquet horizons. Furthermore, scrambling of quantum information is shown to be strongly inhomogeneous, leading to transitions from chaotic to non-chaotic regimes by tuning driving parameters. We finally use our framework to propose a concrete protocol to simulate and measure OTOCs in quantum simulators, by designing an efficient stroboscopic backward time evolution.

arXiv:2405.01642•Physical review. B./Physical review. B•Aug 11, 2025•8 citations

Probing quantum properties of black holes with a Floquet-driven optical lattice simulator

Asmae Benhemou, Georgia Nixon, Aydin Deger +2 more

In the curved spacetime of a black hole, quantum physics gives rise to distinctive effects such as Hawking radiation and maximally fast scrambling. Here, we present a scheme for an analogue quantum simulation of (1 + 1) and (2 + 1)-dimensional black holes using ultracold atoms in a locally Floquet-driven optical lattice. We show how the effective dynamics of the driven system can generate position-dependent tunnelling amplitudes that encode the curved geometry of the black hole. Moreover, we provide a simple and robust scheme to determine the Hawking temperature of a (1+1)D simulated black hole based solely on on-site atom population measurements. Combined with the highly tunable onsite atom-atom interactions typical for cold atoms, our simulator provides a powerful and feasible platform to probe the scrambling of quantum information in black holes. We illustrate the ergodicity of our (2+1)D black-hole simulator by showing numerically that its level statistics in the hard-core limit approaches the ergodic regime faster than a globally homogeneous Hamiltonian.

arXiv:2312.14058•Dec 21, 2023•0 citations

Real-time correlation function of Floquet conformal fields

M. Skou Andersen, Frederik Nørfjand, Nikolaj Thomas Zinner

Conformal field theories (CFT) play an important role in quantum field theories as they allow for exact studies that are hard to access without the conformal symmetries in place. A remarkable recent development is the application of conformal field theory to periodically driven systems, the so-called Floquet-driven CFTs. A number of recent works have found that there are classes of periodically driven ($1+1$)-dimensional CFTs that can be analytically solved, and that show both heating and nonheating phases, as well as unusual properties in terms of information scrambling. Hitherto, most results have focused on the dynamics of such models at stroboscopic times, i.e., samples taken at each period of the time evolution. In this paper, we consider time evolution at arbitrary real times and derive formulas for the exact time propagation of heating and nonheating classes of Floquet-driven CFTs. This requires a subtle treatment of nonstroboscopic time that leads to different interpretations in terms of curved space-time dynamics in these systems compared to previous results in the literature.

arXiv:2011.08494•Physical review. D/Physical review. D.•Mar 10, 2021•17 citations

Geometric approach to inhomogeneous Floquet systems

Bastien Lapierre, Per Moosavi

We present a new geometric approach to Floquet many-body systems described by inhomogeneous conformal field theory in $1+1$ dimensions. It is based on an exact correspondence with dynamical systems on the circle that we establish and use to prove existence of (non)heating phases characterized by the (absence) presence of fixed or higher-periodic points of coordinate transformations encoding the time evolution: Heating corresponds to energy and excitations concentrating exponentially fast at unstable such points while nonheating to pseudoperiodic motion. We show that the heating rate (serving as the order parameter for transitions between these two) can have cusps, even within the overall heating phase, and that there is a rich structure of phase diagrams with different heating phases distinguishable through kinks in the entanglement entropy, reminiscent of Lifshitz phase transitions. Our geometric approach generalizes previous results for a subfamily of similar systems that used only the $\mathfrak{sl}(2)$ algebra to general smooth deformations that require the full infinite-dimensional Virasoro algebra, and we argue that it has wider applicability, even beyond conformal field theory.

arXiv:2010.11268•Physical review. B./Physical review. B•Jun 8, 2021•53 citations
While driven interacting quantum matter is generically subject to heating and scrambling, certain classes of systems evade this paradigm. We study such an exceptional class in periodically driven critical (1+1)-dimensional systems with a spatially modulated but disorder-free time evolution operator. Instead of complete scrambling, the excitations of the system remain well defined. Their propagation is analogous to the evolution along light cones in a curved spacetime obtained by two black holes. The Hawking temperature serves as an order parameter which distinguishes between heating and nonheating phases. Beyond a timescale determined by the inverse Hawking temperature, excitations are absorbed by the black holes resulting in a singular concentration of energy at their horizon. We obtain these results analytically within conformal field theory, capitalizing on a mapping to sine-squared deformed field theories. Furthermore, by means of numerical calculations for an interacting XXZ spin-12 chain, we demonstrate that our findings survive lattice regularization.
We study the dissipative dynamics of a periodically driven inhomogeneous critical lattice model in one dimension. The closed system dynamics starting from pure initial states is well-described by a driven Conformal Field Theory (CFT), which predicts the existence of both heating and non-heating phases in such systems. Heating is inhomogeneous and is manifested via the emergence of black-hole like horizons in the system. The robustness of this CFT phenomenology when considering thermal initial states and open systems remains elusive. First, we present analytical results for the Floquet CFT time evolution for thermal initial states. Moreover, using exact calculations of the time evolution of the lattice density matrix, we demonstrate that for short and intermediate times, the closed system phase diagram comprising heating and non-heating phases, persists for thermal initial states on the lattice. Secondly, in the fully open system with boundary dissipators, we show that the nontrivial spatial structure of the heating phase survives particle-conserving and non-conserving dissipations through clear signatures in mutual information and energy density evolution.
We study universal chaotic dynamics of a large class of periodically driven critical systems described by spatially inhomogeneous conformal field theories. By employing an effective curved spacetime approach, we show that the onset of quantum chaotic correlations, captured by the Lyapunov exponent of out-of-time-order correlators (OTOCs), is set by the Hawking temperature of emergent Floquet horizons. Furthermore, scrambling of quantum information is shown to be strongly inhomogeneous, leading to transitions from chaotic to non-chaotic regimes by tuning driving parameters. We finally use our framework to propose a concrete protocol to simulate and measure OTOCs in quantum simulators, by designing an efficient stroboscopic backward time evolution.
In the curved spacetime of a black hole, quantum physics gives rise to distinctive effects such as Hawking radiation and maximally fast scrambling. Here, we present a scheme for an analogue quantum simulation of (1 + 1) and (2 + 1)-dimensional black holes using ultracold atoms in a locally Floquet-driven optical lattice. We show how the effective dynamics of the driven system can generate position-dependent tunnelling amplitudes that encode the curved geometry of the black hole. Moreover, we provide a simple and robust scheme to determine the Hawking temperature of a (1+1)D simulated black hole based solely on on-site atom population measurements. Combined with the highly tunable onsite atom-atom interactions typical for cold atoms, our simulator provides a powerful and feasible platform to probe the scrambling of quantum information in black holes. We illustrate the ergodicity of our (2+1)D black-hole simulator by showing numerically that its level statistics in the hard-core limit approaches the ergodic regime faster than a globally homogeneous Hamiltonian.
Conformal field theories (CFT) play an important role in quantum field theories as they allow for exact studies that are hard to access without the conformal symmetries in place. A remarkable recent development is the application of conformal field theory to periodically driven systems, the so-called Floquet-driven CFTs. A number of recent works have found that there are classes of periodically driven (1+11+11+1)-dimensional CFTs that can be analytically solved, and that show both heating and nonheating phases, as well as unusual properties in terms of information scrambling. Hitherto, most results have focused on the dynamics of such models at stroboscopic times, i.e., samples taken at each period of the time evolution. In this paper, we consider time evolution at arbitrary real times and derive formulas for the exact time propagation of heating and nonheating classes of Floquet-driven CFTs. This requires a subtle treatment of nonstroboscopic time that leads to different interpretations in terms of curved space-time dynamics in these systems compared to previous results in the literature.
We present a new geometric approach to Floquet many-body systems described by inhomogeneous conformal field theory in 1+11+11+1 dimensions. It is based on an exact correspondence with dynamical systems on the circle that we establish and use to prove existence of (non)heating phases characterized by the (absence) presence of fixed or higher-periodic points of coordinate transformations encoding the time evolution: Heating corresponds to energy and excitations concentrating exponentially fast at unstable such points while nonheating to pseudoperiodic motion. We show that the heating rate (serving as the order parameter for transitions between these two) can have cusps, even within the overall heating phase, and that there is a rich structure of phase diagrams with different heating phases distinguishable through kinks in the entanglement entropy, reminiscent of Lifshitz phase transitions. Our geometric approach generalizes previous results for a subfamily of similar systems that used only the sl(2)\mathfrak{sl}(2)sl(2) algebra to general smooth deformations that require the full infinite-dimensional Virasoro algebra, and we argue that it has wider applicability, even beyond conformal field theory.