Bistability Versus Metastability in Driven Dissipative Rydberg Gases

Letscher, Fabian; Thomas, Oliver S.; Niederprüm, Thomas; Fleischhauer, Michael; Ott, Herwig

doi:10.1103/physrevx.7.021020

Cited by 101 publications

(128 citation statements)

References 51 publications

Supporting

Mentioning

126

Contrasting

Order By: Relevance

“…The sudden switching to the plasma state via an avalanche ionization process leads to the observation of the hysteresis that motivates the term optical bistability. Here, the term bistability is used in that sense that the system jumps from one metastable state to another via this avalanche dynamics [30]. We have identified two mechanisms that contribute to the ionization initiating the plasma formation.…”

Section: Bistability Mechanismmentioning

confidence: 99%

Interplay between thermal Rydberg gases and plasmas

Weller

Shaffer²,

Pfau

et al. 2019

Phys. Rev. A

View full text Add to dashboard Cite

We investigate the phenomenon of bistability in a thermal gas of cesium atoms excited to Rydberg states. We present both measurements and a numerical model of the phenomena based on collisions. By directly measuring the plasma frequency, we show that the origin of the bistable behavior lies in the creation of a plasma formed by ionized Rydberg atoms. Recombination of ions and electrons manifests as fluorescence which allows us to characterize the plasma properties and study the transient dynamics of the hysteresis that occurs. We determine scaling parameters for the point of plasma formation, and verify our numerical model by comparing measured and simulated spectra. These measurements yield a detailed microscopic picture of ionization and avalanche processes occurring in thermal Rydberg gases. From this set of measurements, we conclude that plasma formation is a fundamental ingredient in the optical bistability taking place in thermal Rydberg gases and imposes a limit on usable Rydberg densities for many applications.

show abstract

Section: Bistability Mechanismmentioning

confidence: 99%

Interplay between thermal Rydberg gases and plasmas

Weller

Shaffer²,

Pfau

et al. 2019

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…[13][14][15][16][17][18][19][20][21][22]. Due to their fundamental interest and practical applications, such as enhanced metrological properties [23,24], DPTs have attracted a significant amount of attention, with much work being devoted to study the associated phenomena of bistability [3-5, 22, 25-28], hysteresis [2,29], intermittency [6,26,[29][30][31][32], multimodality [25,31], metastability [33] and symmetry breaking [34][35][36]. All these effects are understood as different manifestations of the coexistence of several non-equilibrium phases.…”

mentioning

confidence: 99%

Symmetries and conservation laws in quantum trajectories: Dissipative freezing

et al. 2019

View full text Add to dashboard Cite

In driven-dissipative systems, the presence of a strong symmetry guarantees the existence of several steady states belonging to different symmetry sectors. Here we show that, when a system with a strong symmetry is initialized in a quantum superposition involving several of these sectors, each individual stochastic trajectory will randomly select a single one of them and remain there for the rest of the evolution. Since a strong symmetry implies a conservation law for the corresponding symmetry operator on the ensemble level, this selection of a single sector from an initial superposition entails a breakdown of this conservation law at the level of individual realizations. Given that such a superposition is impossible in a classical, stochastic trajectory, this is a a purely quantum effect with no classical analogue. Our results show that a system with a closed Liouvillian gap may exhibit, when monitored over a single run of an experiment, a behaviour completely opposite to the usual notion of dynamical phase coexistence and intermittency, which are typically considered hallmarks of a dissipative phase transition. We discuss our results with a simple, realistic model of squeezed superradiance.Driven dissipative systems are ubiquitous in many body physics and cavity QED [1][2][3][4][5][6][7][8][9][10][11][12]. These systems are typically gapped and feature a unique, non-equilibrium steady state. In the regime of a dissipative phase transition (DPT), however, this gap vanishes and the null-space of the Liouvillian is spanned by several compatible steady-states. [13][14][15][16][17][18][19][20][21][22]. Due to their fundamental interest and practical applications, such as enhanced metrological properties [23,24], DPTs have attracted a significant amount of attention, with much work being devoted to study the associated phenomena of bistability [3-5, 22, 25-28], hysteresis [2,29], intermittency [6,26,[29][30][31][32], multimodality [25,31], metastability [33] and symmetry breaking [34][35][36]. All these effects are understood as different manifestations of the coexistence of several non-equilibrium phases. In particular, many experiments will look for intermittency as the hallmark of such phase coexistence [6,26,[29][30][31][32]. Intermittency is a phenomenon defined by a random switching between periods of high and low dynamical activity (for instance in the rate of photon emission). This behaviour, which is observed during a single run of the experiment, is conveniently described using the formalism of quantum jumps in which the system is characterized in terms of a pure wavefunction that undergoes stochastic evolution [37][38][39].The timescale τ of this intermittency is given by the inverse of the Liouvillian gap or asymptotic decay rate (ADR), i.e. the eigenvalue λ 2 of the Liouvillian operator L with the second largest real part [23,40,41]. Since a DPT is defined by a vanishing Liouvillian gap [13,14], it will necessarily imply that τ diverges. In most typical situations, this closing is reached in the thermod...

show abstract

“…From this we would expect linewidths in the order of 50 kHz. Instead, the losses mainly stem from facilitated excitations due to Rydberg–Rydberg interactions in the system . These effects could be reduced in future experiments by changing the principal quantum number or by working with lower atomic densities.…”

Section: An Optical Feshbach Resonance Using Rydberg Moleculesmentioning

confidence: 99%

“…Instead, the losses mainly stem from facilitated excitations due to Rydberg-Rydberg interactions in the system. [65][66][67] These effects could be reduced in future experiments by changing the principal quantum number or by working with lower atomic densities. Provided the losses can be reduced, Rydberg optical Feshbach resonances have great potential in future experiments.…”

Section: An Optical Feshbach Resonance Using Rydberg Moleculesmentioning

confidence: 99%

Excitation of Rydberg Molecules in Ultracold Quantum Gases

Lippe

Eichert

Thomas

et al. 2019

Physica Status Solidi (b)

View full text Add to dashboard Cite

Recent experiments in our group on the excitation of Rydberg molecules in ultracold quantum gases have been reviewed. Quantum gases are a well‐suited environment to excite Rydberg molecules, due to the high atomic density and the perfect control of the internal spin degrees of freedom and the center of mass motion of the atoms. In parallel, the coupling to Rydberg molecules can be used to probe and manipulate the interaction in ultracold quantum gases. In this Feature Article, a comprehensive introduction to the field of Rydberg molecules, including ultralong‐range molecules and butterfly molecules is given. The Rydberg molecules have been characterized spectroscopically and their internal spin structure is discussed. Then, it is shown how these Rydberg molecules work as a tool to monitor the double occupancy in optical lattice experiments and to change the inter‐particle interaction with the help of a so‐called optical Feshbach resonance.

show abstract

Bistability Versus Metastability in Driven Dissipative Rydberg Gases

Cited by 101 publications

References 51 publications

Interplay between thermal Rydberg gases and plasmas

Interplay between thermal Rydberg gases and plasmas

Symmetries and conservation laws in quantum trajectories: Dissipative freezing

Excitation of Rydberg Molecules in Ultracold Quantum Gases

Contact Info

Product

Resources

About