Stabilizing a discrete time crystal against dissipation

Droenner, Leon; Finsterhölzl, Regina; Heyl, Markus; Carmele, Alexander

doi:10.48550/arxiv.1902.04986

Cited by 6 publications

(7 citation statements)

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“…Might we consider some open systems to be time crystals? As we already saw in the Dicke model, a dissipative bath (row 6, Figure 3) can play a significant role in preventing the drive-induced heating of a Floquet system and thus stabilize a wider range of strongly interacting time crystalline phases [13,44,[114][115][116][117]. In systems near thermal equilibrium, a bath that is itself in equilibrium will help the system to reach equilibrium.…”

Section: Dissipative Stabilization Open Systems and Classical Time Cr...mentioning

confidence: 81%

Discrete Time Crystals

Else

Monroe

Nayak

et al. 2020

Annu. Rev. Condens. Matter Phys.

254

176

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Experimental advances have allowed for the exploration of nearly isolated quantum many-body systems whose coupling to an external bath is very weak. A particularly interesting class of such systems is those which do not thermalize under their own isolated quantum dynamics. In this review, we highlight the possibility for such systems to exhibit new non-equilibrium phases of matter. In particular, we focus on "discrete time crystals", which are many-body phases of matter characterized by a spontaneously broken discrete time translation symmetry. We give a definition of discrete time crystals from several points of view, emphasizing that they are a non-equilibrium phenomenon, which is stabilized by many-body interactions, with no analog in non-interacting systems. We explain the theory behind several proposed models of discrete time crystals, and compare a number of recent realizations, in different experimental contexts.

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Section: Dissipative Stabilization Open Systems and Classical Time Cr...mentioning

confidence: 81%

Discrete Time Crystals

Else

Monroe

Nayak

et al. 2020

Annu. Rev. Condens. Matter Phys.

254

176

View full text Add to dashboard Cite

show abstract

“…An ingenious proposal for survival of a DTC despite a specific form of communication with the environmentmuch less artificial than the two-leg ladder constructed above - [177] was made in the context of a kicked random Ising chain subject to uncontrolled radiative decay. Using information on the photons likely to be emitted, one can place a mirror to reflect these at a judiciously chosen distance so that their subsequent reabsorption by the system occurs with a phase shift conducive to stabilising the DTC.…”

Section: Open Many-body Quantum Systemsmentioning

confidence: 99%

A Brief History of Time Crystals

Khemani,

Moessner,

Sondhi

2019

Preprint

100

167

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The idea of breaking time-translation symmetry has fascinated humanity at least since ancient proposals of the perpetuum mobile. Unlike the breaking of other symmetries, such as spatial translation in a crystal or spin rotation in a magnet, time translation symmetry breaking (TTSB) has been tantalisingly elusive. We review this history up to recent developments which have shown that discrete TTSB does takes place in periodically driven (Floquet) systems in the presence of many-body localization (MBL). Such Floquet time-crystals represent a new paradigm in quantum statistical mechanics -that of an intrinsically out-of-equilibrium many-body phase of matter with no equilibrium counterpart.We include a compendium of the necessary background on the statistical mechanics of phase structure in manybody systems, before specializing to a detailed discussion of the nature, and diagnostics, of TTSB. In particular, we provide precise definitions that formalize the notion of a time-crystal as a stable, macroscopic, conservative clockexplaining both the need for a many-body system in the infinite volume limit, and for a lack of net energy absorption or dissipation. Our discussion emphasizes that TTSB in a time-crystal is accompanied by the breaking of a spatial symmetry -so that time-crystals exhibit a novel form of spatiotemporal order.We also cover a range of related phenomena, including various types of long (but not infinitely long)-lived prethermal time-crystals, and expose the roles played by symmetries -exact and (emergent) approximate -and their breaking. We clarify the distinctions between macroscopic many-body time-crystals and other ostensibly similar dynamical phenomena dating as far back as the works of Faraday and Mathieu. En route, we encounter Wilczek's suggestion from a few years ago that macroscopic systems should exhibit time translation symmetry breaking in their ground states, together with a theorem that ruled this out. We also analyse pioneering recent experimental work detecting signatures of time crystallinity in a variety of different platforms, providing a detailed theoretical explanation of the physics in each case. In all existing experiments, the system does not realize a 'true' time-crystal phase in an asymptotic sense, and our analysis helps identify necessary ingredients for improvements in future experiments.

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“…With exception of phonon modes with constant dispersion, in which the Heisenberg inductive equations of motion is numerically exact, only the realtime path integral method is capable to treat the coupling of QDs to a continuum of acoustic phonons exactly for time-dependent excitation scenarios. This method relies on slicing the time evolution into discrete steps and is similar to recently widely employed time-evolving block decimation or matrix-product state methods [111,112,114,115,145]. These models take into account not only the non-Markovian features of the system dynamics but also the growing degree of entanglement between system and reservoir states due to excitation exchange and information backflow.…”

Section: F Phonon-assisted Population Inversion (Real-time Path Integ...mentioning

confidence: 99%

Non-Markovian features in semiconductor quantum optics: quantifying the role of phonons in experiment and theory

Carmele

Reitzenstein

2019

Nanophotonics

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We discuss phonon-induced non-Markovian and Markovian features in QD-based optics. We cover lineshapes in linear absorption experiments, phonon-induced incoherence in the Heitler regime, and memory correlations in two-photon coherences. To quantitatively and qualitatively understand the underlying physics, we present several theoretical models which model the non-Markovian properties of the electron-phonon interaction accurately in different regimes. Examples are the Heisenberg equation of motion approach, the polaron master equation, and Liouville-propagator techniques in the independent boson limit and beyond via the path-integral method. Phenomenological modeling overestimates typically the dephasing due to the finite memory kernel of phonons and we give instructive examples of phonon-mediated coherence such as phonon-dressed anticrossings in Mollow physics, robust quantum state preparation, cavity-feeding and the stabilization of the collapse and revival phenomenon in the strong coupling limit. * alex@itp.tu-berlin.de arXiv:1904.10905v1 [quant-ph] 24 Apr 2019 of exciting phenomena in these systems due to the ubiquitous non-Markovian electron-phonon and electron-electron dynamics. To name a few, quantum wires show phonon-enabled thermal conductivity [63] based on a universal quantum of thermal conductance [64]. Pronounced non-Markovian decoherence is demonstrated in localized nanotube excitons [32] and also phonon-assisted Anderson localization phenomena have been investigated [65]. In quantum wells, coherent acoustic oscillations are studied [66], and non-equilibrium cooling effects bottlenecked by non-Markovian phonon dynamics have been discussed [67]. Four-wave mixing techniques allow to study and characterize giant excitonic resonances [68,69], and via two-dimensional coherent spectroscopy techniques incoherent exciton-phonon Green's function can be probed and extracted in disordered quantum wells [70,71].Moreover, optical and electronic two-dimensional spectroscopy has drawn a lot interest recently, as non-Markovian, anomalous lineshapes and relaxation/scattering processes can be characterized and studied in depth. For example, the study of signatures of spatially correlated noise and non-secular effects [72] has been performed, the read-out of Rabi oscillations in QDs [73], exciton coherence at room temperature [74] investigated, systematic study of dephasing processes including quadratic electron-phonon coupling for elevated temperatures [75,76] and phonon sidebands in transition metal dichalcogenides have been demonstrated [77]. Despite the exciting results in higher-dimensional nanostructures and two-dimensional coherent spectroscopy, we focus in the following on a single material platform, semiconductor QDs. This allows us to discuss in detail instructive experimental examples in which the phonon interaction is the dominant source of decoherence and theoretical models which are capable to capture their specific details and can partially be treated even analytically. These models are, however, not li...

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Stabilizing a discrete time crystal against dissipation

Cited by 6 publications

References 0 publications

Discrete Time Crystals

Discrete Time Crystals

A Brief History of Time Crystals

Non-Markovian features in semiconductor quantum optics: quantifying the role of phonons in experiment and theory

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