Moiré heterostructures as a condensed-matter quantum simulator

Nature Physics, Journal Year: 2021, Volume and Issue: 17(2), P. 155 - 163

Published: Feb. 1, 2021

Language: Английский

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Relevance of the Quadratic Diamagnetic and Self-Polarization Terms in Cavity Quantum Electrodynamics

ACS Photonics, Journal Year: 2020, Volume and Issue: 7(4), P. 975 - 990

Published: Feb. 26, 2020

Experiments at the interface of quantum optics and chemistry have revealed that strong coupling between light matter can substantially modify chemical physical properties molecules solids. While theoretical description such situations is usually based on nonrelativistic electrodynamics, which contains quadratic light–matter terms, it commonplace to disregard these terms restrict treatment purely bilinear couplings. In this work, we clarify origin substantial impact most common diamagnetic self-polarization highlight why neglecting them lead rather unphysical results. Specifically, demonstrate their relevance by showing leads loss gauge invariance, basis set dependence, disintegration (loss bound states) any system in limit, radiation ground state, an artificial dependence static dipole. Besides providing important guidance for modeling strongly coupled systems, presented results also indicate conditions under those effects might become accessible.

Language: Английский

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Quantum Information and Algorithms for Correlated Quantum Matter

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(5), P. 3061 - 3120

Published: Dec. 16, 2020

Discoveries in quantum materials, which are characterized by the strongly quantum-mechanical nature of electrons and atoms, have revealed exotic properties that arise from correlations. It is promise materials for information science superimposed with potential new computational algorithms to discover inspires this Review. We anticipate be discovered developed next years will transform areas processing including communication, storage, computing. Simultaneously, efforts toward developing algorithmic approaches simulation advanced calculation methods many-body systems enable major advances functional their deployment. The advent computing brings possibilities eliminating exponential complexity has stymied correlated on high-performance classical computers. Here, we review predict understand behavior matter. interdisciplinary topics covered necessitates a common language integrate ideas these fields. aim provide while weaving together fields across electronic structure theory, electrodynamics, algorithm design, open systems. Our Review timely presenting state-of-the-art field nonexponential matter applications grand-challenge problems. Looking future, at intersection matter, envision seminal predicting states describing excitonic large-scale entangled states, better understanding high-temperature superconductivity, quantifying system dynamics.

Language: Английский

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The 2021 ultrafast spectroscopic probes of condensed matter roadmap

Journal of Physics Condensed Matter, Journal Year: 2021, Volume and Issue: 33(35), P. 353001 - 353001

Published: May 5, 2021

In the 60 years since invention of laser, scientific community has developed numerous fields research based on these bright, coherent light sources, including areas imaging, spectroscopy, materials processing and communications. Ultrafast spectroscopy imaging techniques are at forefront into light-matter interaction shortest times accessible to experiments, ranging from a few attoseconds nanoseconds. Light pulses provide crucial probe dynamical motion charges, spins, atoms picosecond, femtosecond, down attosecond timescales, none which even with fastest electronic devices. Furthermore, strong can drive unusual phases, exotic properties. this roadmap we describe current state-of-the-art in experimental theoretical studies condensed matter using ultrafast probes. each contribution, authors also use their extensive knowledge highlight challenges predict future trends.

Language: Английский

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Dark state semilocalization of quantum emitters in a cavity

Physical review. B./Physical review. B, Journal Year: 2020, Volume and Issue: 102(14)

Published: Oct. 28, 2020

We study a disordered ensemble of quantum emitters collectively coupled to lossless cavity mode. The latter is found modify the localization properties ``dark'' eigenstates, which exhibit character being localized on multiple noncontiguous sites. denote such states as semilocalized and characterize them by means standard measures. show that those can very efficiently contribute coherent energy transport. Our paper underlines important role dark in systems with strong light-matter coupling.

Language: Английский

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Large Enhancement of Ferromagnetism under a Collective Strong Coupling of YBCO Nanoparticles

Nano Letters, Journal Year: 2021, Volume and Issue: 21(10), P. 4365 - 4370

Published: May 4, 2021

Light–Matter strong coupling in the vacuum limit has been shown, over past decade, to enhance material properties. Oxide nanoparticles are known exhibit weak ferromagnetism due vacancies lattice. Here we report 700-fold enhancement of YBa2Cu3O7–x under a cooperative at room temperature. The magnetic moment reaches 0.90 μB/mol, and with such high value, it competes superconductivity low temperatures. This temperature suggest that is new tool for development next-generation spintronic nanodevices.

Language: Английский

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Making ab initio QED functional(s): Nonperturbative and photon-free effective frameworks for strong light–matter coupling

Proceedings of the National Academy of Sciences, Journal Year: 2021, Volume and Issue: 118(41)

Published: Oct. 8, 2021

Strong light-matter coupling provides a promising path for the control of quantum matter where latter is routinely described from first-principles. However, combining quantized nature light with this ab initio tool set challenging and merely developing, as coupled Hilbert space conceptually different computational cost quickly becomes overwhelming. In work, we provide non-perturbative photon-free formulation electrodynamics (QED) in long-wavelength limit, which formulated solely on can serve an accurate starting point such methods. The present extension mechanics that recovers exact results QED zero- infinite-coupling infinite-frequency well homogeneous limit constructively increase its accuracy. We show how be used to devise approximations quantum-electrodynamical density-functional theory (QEDFT), turn also allows extend ansatz full minimal-coupling problem non-adiabatic situations. Finally, simple local-density-type functional takes strong transverse photon-degrees freedom into account includes correct frequency polarization dependence. This first QEDFT accounts while remaining computationally enough allow application large range systems. All seamless periodic

Language: Английский

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Polaritonic Hofstadter butterfly and cavity control of the quantized Hall conductance

Physical review. B./Physical review. B, Journal Year: 2022, Volume and Issue: 105(20)

Published: May 19, 2022

In a previous work [Phys. Rev. Lett. 123, 047202 (2019)] translationally invariant framework called quantum-electrodynamical Bloch (QED-Bloch) theory was introduced for the description of periodic materials in homogeneous magnetic fields and strongly coupled to quantized photon field optical limit. For such systems, we show that QED-Bloch predicts existence fractal polaritonic spectra as function cavity coupling strength. addition, energy spectrum relative flux find terahertz can modify standard Hofstadter butterfly. limit no field, captures well-known butterfly be used 2D strong fields, which are great experimental interest. As further application, consider Landau levels under confinement alters Hall conductance plateaus modified $\sigma_{xy}=e^2\nu/h(1+\eta^2)$ by light-matter $\eta$. Most aforementioned phenomena should experimentally accessible corresponding implications discussed.

Language: Английский

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Light-matter coupling and quantum geometry in moiré materials

Physical review. B./Physical review. B, Journal Year: 2021, Volume and Issue: 104(6)

Published: Aug. 16, 2021

Quantum geometry has been identified as an important ingredient for the physics of quantum materials and especially flat-band systems, such moir\'e materials. On other hand, coupling between light matter is key importance across disciplines Floquet cavity engineering solids. Here we present fundamental relations light-matter Bloch wave functions, with a particular focus on materials, in which quenching electronic kinetic energy could allow one to reach limit strong more easily than highly dispersive systems. We show that, despite fact that flat bands have vanishing band velocities curvatures, couples them via geometric contributions. Specifically, intraband metric allows diamagnetic inside band; interband Berry connection governs dipole matrix elements bands. illustrate these effects two representative model systems: (i) sawtooth chain single (ii) tight-binding twisted bilayer graphene. For highlight by demonstrating nonvanishing band. explore twist-angle dependence various elements. Furthermore, at magic angle corresponding almost bands, Floquet-topological gap opening under irradiation circularly polarized nearly Fermi velocity. discuss how findings provide design principles tools light-matter-coupling-based control emergent properties

Language: Английский

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Cavity QED with quantum gases: new paradigms in many-body physics

Advances In Physics, Journal Year: 2021, Volume and Issue: 70(1), P. 1 - 153

Published: Jan. 2, 2021

We review the recent developments and current status in field of quantum-gas cavity QED. Since first experimental demonstration atomic self-ordering a system composed Bose-Einstein condensate coupled to quantized electromagnetic mode high-$Q$ optical cavity, has rapidly evolved over past decade. The composite quantum-gas--cavity systems offer opportunity implement, simulate, experimentally test fundamental solid-state Hamiltonians, as well realize non-equilibrium many-body phenomena beyond conventional condensed-matter scenarios. This hinges on unique possibility design control open quantum environments photon-induced tunable-range interaction potentials for atoms using tailored pump lasers dynamic fields. Notable examples range from Hubbard-like models with long-range interactions exhibiting lattice-supersolid phase, emergent magnetic orderings quasicrystalline symmetries, appearance gauge topological phases. Experiments have managed load spin-polarized spinful gases into various geometries engineer versatile interactions. led observation spontaneous discrete continuous symmetry breaking soft-modes supersolidity, density spin self-ordering, spin-orbit coupling, dynamical self-ordered phases among others. In addition, setups new platforms quantum-enhanced measurements. this review, starting an introduction basic models, we pedagogically summarize broad theoretical put them perspective near future state-of-art experiments.

Language: Английский

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