Research Repository

See what's under the surface


Discrete time crystals in the absence of manifest symmetries or disorder in open quantum systems (2019)
Journal Article
Gambetta, F., Carollo, F., Marcuzzi, M., Garrahan, J., & Lesanovsky, I. (2019). Discrete time crystals in the absence of manifest symmetries or disorder in open quantum systems. Physical Review Letters, 122(1), doi:10.1103/physrevlett.122.015701

We establish a link between metastability and a discrete time-crystalline phase in a periodically driven open quantum system. The mechanism we highlight requires neither the system to display any microscopic symmetry nor the presence of disorder, but... Read More

Non-equilibrium absorbing state phase transitions in discrete-time quantum cellular automaton dynamics on spin lattices (2018)
Journal Article
Lesanovsky, I., Macieszczak, K., & Garrahan, J. P. (2018). Non-equilibrium absorbing state phase transitions in discrete-time quantum cellular automaton dynamics on spin lattices. Quantum Science and Technology, doi:10.1088/2058-9565/aaf831

We introduce a discrete-time quantum dynamics on a two-dimensional lattice that describes the evolution of a $1+1$-dimensional spin system. The underlying quantum map is constructed such that the reduced state at each time step is separable. We show... Read More

Dynamical criticality in open systems: nonperturbative physics, microscopic origin, and direct observation (2018)
Journal Article
Pérez-Espigares, C., Carollo, F., Garrahan, J. P., & Hurtado, P. I. (2018). Dynamical criticality in open systems: nonperturbative physics, microscopic origin, and direct observation. Physical Review E, 98(6), doi:10.1103/physreve.98.060102

Driven diffusive systems may undergo phase transitions to sustain atypical values of the current. This leads in some cases to symmetry-broken space-time trajectories which enhance the probability of such fluctuations. Here, we shed light on both the... Read More

Catching and reversing quantum jumps and thermodynamics of quantum trajectories (2018)
Journal Article
Garrahan, J. P., & Guta, M. (2018). Catching and reversing quantum jumps and thermodynamics of quantum trajectories. Physical Review A, 98(5), doi:10.1103/PhysRevA.98.052137

A recent experiment by Minev et. al [arXiv:1803.00545] demonstrated that in a dissipative (artificial) 3-level atom with strongly intermittent dynamics it is possible to " catch and reverse " a quantum jump " mid-flight " : by the conditional applica... Read More

Singularities in large deviations of work in quantum quenches (2018)
Journal Article
Rotondo, P., Minář, J., Garrahan, J. P., Lesanovsky, I., & Marcuzzi, M. (2018). Singularities in large deviations of work in quantum quenches. Physical Review B, 98(18), doi:10.1103/physrevb.98.184303

We investigate large deviations of the work performed in a quantum quench across two different phases separated by a quantum critical point, using as an example the Dicke model quenched from its superradiant to its normal phase. We extract the distri... Read More

Unified thermodynamic uncertainty relations in linear response (2018)
Journal Article
Macieszczak, K., Brandner, K., & Garrahan, J. P. (2018). Unified thermodynamic uncertainty relations in linear response. Physical Review Letters, 121(13), doi:10.1103/physrevlett.121.130601

Thermodynamic uncertainty relations (TURs) are recently established relations between the relative uncertainty of time-integrated currents and entropy production in non-equilibrium systems. For small perturbations away from equilibrium, linear respon... Read More

Enhancing correlation times for edge spins through dissipation (2018)
Journal Article
Vasiloiu, L. M., Carollo, F., & Garrahan, J. P. (2018). Enhancing correlation times for edge spins through dissipation. Physical Review B, 98(9), (1-6). doi:10.1103/physrevb.98.094308. ISSN 2469-9950

Spin chains with open boundaries, such as the transverse field Ising model, can display coherence times for edge spins that diverge with the system size as a consequence of almost conserved operators, the so-called strong zero modes. Here we discuss... Read More

Current fluctuations in boundary-driven quantum spin chains (2018)
Journal Article
Carollo, F., Garrahan, J. P., & Lesanovsky, I. (2018). Current fluctuations in boundary-driven quantum spin chains. Physical Review B, 98(9), (1-9). doi:10.1103/physrevb.98.094301. ISSN 2469-9950

Boundary-driven quantum spin chains are paradigmatic nonequilibrium systems featuring the presence of particle currents. In general, it may not be possible to distinguish an incoherent type of particle transport from a truly quantum coherent one thro... Read More

Glassy dynamics due to a trajectory phase transition in dissipative Rydberg gases (2018)
Journal Article
Pérez-Espigares, C., Lesanovsky, I., Garrahan, J. P., & Gutiérrez, R. (2018). Glassy dynamics due to a trajectory phase transition in dissipative Rydberg gases. Physical Review A, 98(2), doi:10.1103/physreva.98.021804. ISSN 2469-9926

The physics of highly excited Rydberg atoms is governed by blockade or exclusion interactions that hinder the excitation of atoms in the proximity of a previously excited one. This leads to cooperative effects and a relaxation dynamics displaying spa... Read More

Phases of quantum dimers from ensembles of classical stochastic trajectories (2018)
Journal Article
Oakes, T., Powell, S., Castelnovo, C., Lamacraft, A., & Garrahan, J. P. (2018). Phases of quantum dimers from ensembles of classical stochastic trajectories. Physical Review B, 98(6), doi:10.1103/PhysRevB.98.064302. ISSN 2469-9950

We study the connection between the phase behaviour of quantum dimers and the dynamics of classical stochastic dimers. At the so-called Rokhsar–Kivelson (RK) point a quantum dimer Hamiltonian is equivalent to the Markov generator of the dynamics of c... Read More

Quantum slow relaxation and metastability due to dynamical constraints (2018)
Journal Article
Lan, Z., van Horssen, M., Powell, S., & Garrahan, J. P. (2018). Quantum slow relaxation and metastability due to dynamical constraints. Physical Review Letters, 121(4), (1-6). doi:10.1103/PhysRevLett.121.040603. ISSN 0031-9007

One of the general mechanisms that give rise to the slow cooperative relaxation characteristic of classical glasses is the presence of kinetic constraints in the dynamics. Here we show that dynamical constraints can similarly lead to slow thermalisat... Read More

Making rare events typical in Markovian open quantum systems (2018)
Journal Article
Carollo, F., Garrahan, J. P., Lesanovsky, I., & Pérez-Espigares, C. (2018). Making rare events typical in Markovian open quantum systems. Physical Review A, 98(1), doi:10.1103/physreva.98.010103. ISSN 2469-9926

Large dynamical fluctuations—atypical realizations of the dynamics sustained over long periods of time—can play a fundamental role in determining the properties of collective behavior of both classical and quantum nonequilibrium systems. Rare dynamic... Read More

Solvation in space-time: pre-transition effects in trajectory space (2018)
Journal Article
Katira, S., Garrahan, J. P., & Mandadapu, K. K. (2018). Solvation in space-time: pre-transition effects in trajectory space. Physical Review Letters, 120(26), doi:10.1103/PhysRevLett.120.260602. ISSN 0031-9007

We demonstrate pre-transition effects in space--time in trajectories of systems in which the dynamics displays a first-order phase transition between distinct dynamical phases. These effects are analogous to those observed for thermodynamic first-ord... Read More

Rare behavior of growth processes via umbrella sampling of trajectories (2018)
Journal Article
Klymko, K., Geissler, P. L., Garrahan, J. P., & Whitelam, S. (2018). Rare behavior of growth processes via umbrella sampling of trajectories. Physical Review E, 97(3), doi:10.1103/PhysRevE.97.032123. ISSN 2470-0045

We compute probability distributions of trajectory observables for reversible and irreversible growth processes. These results reveal a correspondence between reversible and irreversible processes, at particular points in parameter space, in terms of... Read More

Open quantum generalisation of Hopfield neural networks (2018)
Journal Article
Rotondo, P., Marcuzzi, M., Garrahan, J. P., Lesanovsky, I., & Müller, M. (2018). Open quantum generalisation of Hopfield neural networks. Journal of Physics A: Mathematical and Theoretical, 51(11), doi:10.1088/1751-8121/aaabcb. ISSN 1751-8113

We propose a new framework to understand how quantum effects may impact on the dynamics of neural networks. We implement the dynamics of neural networks in terms of Markovian open quantum systems, which allows us to treat thermal and quantum coherent... Read More

Fluctuating hydrodynamics, current fluctuations and hyperuniformity in boundary-driven open quantum chains (2017)
Journal Article
Carollo, F., Garrahan, J. P., Lesanovsky, I., & Pérez-Espigares, C. (2017). Fluctuating hydrodynamics, current fluctuations and hyperuniformity in boundary-driven open quantum chains. Physical Review E, 96, doi:10.1103/PhysRevE.96.052118. ISSN 2470-0045

We consider a class of either fermionic or bosonic non-interacting open quantum chains driven by dissipative interactions at the boundaries and study the interplay of coherent transport and dissipative processes, such as bulk dephasing and diffusion.... Read More

Metastable decoherence-free subspaces and electromagnetically induced transparency in interacting many-body systems (2017)
Journal Article
Macieszczak, K., Zhou, Y., Hofferberth, S., Garrahan, J. P., Li, W., & Lesanovsky, I. (2017). Metastable decoherence-free subspaces and electromagnetically induced transparency in interacting many-body systems. Physical Review A, 96(4), doi:10.1103/PhysRevA.96.043860. ISSN 2469-9926

We investigate the dynamics of a generic interacting many-body system under conditions of electromagnetically induced transparency (EIT). This problem is of current relevance due to its connection to non-linear optical media realized by Rydberg atoms... Read More

Similarity of ensembles of trajectories of reversible and irreversible growth processes (2017)
Journal Article
Klymko, K., Garrahan, J. P., & Whitelam, S. (2017). Similarity of ensembles of trajectories of reversible and irreversible growth processes. Physical Review E, 96(4), doi:10.1103/PhysRevE.96.042126. ISSN 2470-0045

Models of bacterial growth tend to be “irreversible,” allowing for the number of bacteria in a colony to increase but not to decrease. By contrast, models of molecular self- assembly are usually “reversible,” allowing for the addition and removal of... Read More

Phase transitions in electron spin resonance under continuous microwave driving (2017)
Journal Article
Karabanov, A., Rose, D. C., Köckenberger, W., Garrahan, J. P., & Lesanovsky, I. (in press). Phase transitions in electron spin resonance under continuous microwave driving. Physical Review Letters, 119, doi:10.1103/PhysRevLett.119.150402. ISSN 0031-9007

We study an ensemble of strongly coupled electrons under continuous microwave irradiation interacting with a dissipative environment, a problem of relevance to the creation of highly polarized non-equilibrium states in nuclear magnetic resonance. We... Read More