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Floquet engineering is often limited by weak light–matter coupling and heating. Now it is shown that exciton-driven fields in monolayer semiconductors produce stronger, longer-lived Floquet effects and reveal hybridization linked to excitonic phases.

Here, the authors show the emergence of valley-polarized Floquet-Bloch states in 2H-WSe₂ upon below-band-gap driving using circularly polarized light.

The feasibility of Floquet engineering in graphene has been called into question due to its fast decoherence processes. Measurements of graphene’s photoemission spectrum now support the generation of Floquet states in this material.

Periodic laser light can modify the electronic properties of solids and offers a path to create new material phases. In a topological antiferromagnet, periodic driving with opposite light helicities is now shown to produce distinct Dirac mass gaps.

Creating and controlling topological states of matter has become a central goal in condensed matter physics. Here, the authors report a predictive Floquet engineering of various topological phases in Na₃Bi by using femtosecond laser pulses.

In black phosphorus, a model semiconductor, analysis of time and angle-resolved photoemission spectroscopy measurements demonstrates a strong light-induced band renormalization with light polarization dependence, suggesting pseudospin-selective Floquet band engineering.

The authors study the light-driven dynamics of attractive and repulsive Fermi polarons in monolayer WSe₂. They show that the resonance shifts of Fermi polarons are valley-selective; the resonance shifts of attractive polarons increase with Fermi-sea density, while those of repulsive polarons decrease.

Large-scale atom interferometers enable precise measurements of fundamental constants and novel sensors. This study uses Floquet formalism to create an optimal transported state, resulting in an efficient large-momentum-transfer interferometer, advancing largescale interferometers.

A frequency detuning between two pump lasers enables an exciton–polariton Floquet optical lattice and a polariton ‘conveyor belt’. The findings pave the way for Floquet engineering in polariton condensates.

Condensed matter research has seen prominent recent advances in ultrafast optical manipulation and topological materials. Here, Sentef et al. simulate the development of the photoemission-measured band structure of Floquet states in graphene excited by low-frequency circularly-polarized laser pulses.

Floquet engineering aims at inducing new properties in materials with light. Here the authors have used pulses of variable durations, to investigate its applicability in the femtosecond domain. Surprisingly, they found that it holds to the few-cycle limit.

Time- and angle-resolved photoelectron spectroscopy experiments are used to monitor the transition between Floquet–Bloch and Volkov states in the topological insulator Bi₂Se₃.

Organic semiconductors employed in light-emitting diodes (OLEDs) allow for magnetic resonance studies that explore light-matter interactions in the ultrastrong-drive regime, where the Rabi frequency exceeds the Larmor frequency. The authors report the formation of Floquet spin states in OLEDs.

An effective Hamiltonian exhibiting \({\Bbb Z}_2\) symmetry has been engineered by implementing a Floquet-based method on ultracold bosons in an optical lattice, providing a first step towards quantum simulation of \({\Bbb Z}_2\) lattice gauge theories with ultracold matter.

The build-up and dephasing of Floquet-–Bloch bands is visualized in both subcycle band-structure videography and quantum theory, revealing the interplay of strong-field intraband and interband excitations in a non-equilibrium Floquet picture.

One-way sound propagation has been recently proposed in the context of topological acoustics, but is challenged by introducing uniform media motion. Here, Fleury et al.present a practical scheme to achieve topological propagation by modulating in time the acoustic properties of a lattice of resonators, resembling Floquet topological insulators in condensed matter.

In 2H semiconducting transition-metal dichalcogenides the valley-selective excitation has been achieved with circularly polarized photons. Here, the authors show that circularly polarized phonons produce a valley-dependent dynamic spin state as a result of strong spin-phonon coupling.

The interaction of strong laser fields with tungsten disulfide leads to light-dressed Floquet replica of excitonic states, which manifest as new features in the transient absorption spectrum.

The authors introduce a method to assess the stability of periodic (seasonal) systems without the need for complex data pre-processing and show that it can be used to predict the onset of glacier surges and understand patterns in Amazon vegetation resilience.

Non-equilibrium systems subject to periodic driving fields, known as Floquet materials, can host unique topological phases without static counterpart. This work targets the link between Floquet physics and cavity-QED systems, and unveils the emergence of quantum anomalous phases in the latter, pointing to the important entangled light-matter dynamics.

Subject to a periodic drive, quantum materials can develop nontrivial bulk topological state, termed a Floquet topological insulator, which differs from its static counterpart due to the nontrivial role played by the time dimension. Here, the authors theoretically demonstrate that such dynamic topology can be probed by bulk dislocation lattice defects, realizable in state-of-the-art experiments in quantum crystals, cold atomic systems and various metamaterials.

For solid-state experiments, exactly solvable quantum light matter models, where the quantum nature of light is relevant, are scarce. Here, the authors introduce an exactly solvable model, where a one-dimensional tight-binding chain is coupled to a single cavity mode and derive analytic expressions for the ground state, where the photons are squeezed due to the light-matter coupling.

Parity-time symmetric systems allow one to study new types of Hamiltonians which could have potential impact on our understanding of nonlinear physics. The authors investigate the energy stored in an electronic Floquet system and demonstrate that such a setup can be used to study the dynamics of dissipative parity-time symmetric systems.

Strong light-matter interaction provides opportunities for engineering electronic symmetry on an ultrafast timescale by forming photon-dressed states called Floquet-Bloch states. Here, the authors observe parity manipulation of Floquet-Bloch states by light fields in a model semiconductor - black phosphorus.

Experimental realizations of discrete time crystals have mainly involved 1D models with Ising-like couplings. Here, the authors realize a 2D discrete time crystal with anisotropic Heisenberg coupling on a quantum simulator based on superconducting qubits, uncovering a rich phase diagram.

Digital quantum simulations of Kitaev’s honeycomb model are realized for two-dimensional fermionic systems using a reconfigurable atom-array processor and used to study the Fermi–Hubbard model on a square lattice.

The existence of a long-lived, prethermal regime in many-body systems with tunable heating rates, driven by structured random protocols, is observed using a 78-qubit superconducting quantum processor.

A superconducting quantum computer is used to realize an out-of-equilibrium topologically ordered state, which hosts anyonic excitations.

Studying many-body quantum chaos on current quantum hardware is hindered by noise and limited scalability. Now it is shown that a superconducting processor, combined with error mitigation, can accurately simulate dual-unitary circuit dynamics.

Previous work on periodically driven many-body systems has demonstrated the formation of time crystals that break time-translation symmetry. Now, more general phases with partial temporal ordering have been realized.

Light–matter interaction in 2D and topological materials provides a fascinating control knob for inducing emergent, non-equilibrium properties and achieving new functionalities in the ultrafast timescale. This Review discusses recent experimental progress on the light-induced phenomena and provides perspectives on the opportunities of proposed light-induced phenomena, as well as open experimental challenges.

Experiments demonstrate the powerful capabilities of ultracold molecules to study dynamics in the context of quantum magnetism, and create new possibilities for studying quantum physics with ultracold molecules more broadly.

The experimental demonstration of many-body signal amplification in a solid-state, room-temperature quantum sensor is reported.

Getting a grip on the chaotic properties of quantum systems is difficult. Now, the effect of translational invariance in space in time in an ensemble of random quantum circuits is shown to lead to largely universal scaling laws describing the system without the need of knowing microscopic details.

The optical trapping of ultracold atoms allows for the simulation and controlled exploration of phenomena normally found in condensed matter systems. Here, the authors demonstrate spin–orbit coupling between lattice band pseudospins in a Bose-Einstein condensate of ultracold atoms.

Nonlinear multidimensional spectroscopy that can image the sub-cycle dynamics of strongly correlated systems on the sub-femtosecond timescale is demonstrated by using the carrier–envelope-phase dependence of the correlated multielectron response to decode the complex interplay between different many-body states.

Here, the authors perform measurements of the interference effects of Cooper Quartets (CQ), observed in a multi-terminal graphene Josephson junction where two terminals are tied by a flux loop. By biasing the superconducting contacts, they identify a superconducting branch attributed to CQ currents, and present evidence for interference between different CQ processes.

Internal degrees of freedom allow to expand the effective dimensionality of a system along “synthetic” dimensions. Here, the authors demonstrate this by modulating a ring resonator at frequencies commensurate with its mode spacing, and are able to directly measure its synthetic band structure.

Conical intersections, a hallmark of polyatomic molecules, can be induced with light, leading to new reaction pathways. Here, the authors show that intense fields can create complex, beyond-conical intersections even in diatomics, resulting in an unexpected angular distribution of fragment ions.

Quantum simulations of chemistry and materials are challenging due to the complexity of correlated systems. A framework based on reconfigurable qubit architectures and digital–analogue simulations provides a hardware-efficient path forwards.

A time crystal is a state of matter that shows robust oscillations in time, and although forbidden in equilibrium, a discrete time crystal has now been observed in a periodically driven quantum system.

In the dipolar XY model, quench dynamics from a polarized initial state lead to spin squeezing that improves with increasing system size, and two refinements show further enhanced squeezing and extended lifetime of the squeezed state by freezing its dynamics.