Year: 2024
Type: article
Abstract: We consider the quantum reaction-diffusion dynamics in $d$ spatial dimensions of a Fermi gas subject to binary annihilation reactions $A+A\ensuremath{\rightarrow}\ensuremath{\emptyset}$. These systems display collective nonequilibrium long-time behavior, which is signalled by an algebraic decay of the particle density. Building on the Keldysh formalism, we devise a field theoretical approach for the reaction-limited regime, where annihilation reactions are scarce. Combining a perturbative expansion of the dissipative interaction with Euler-hydrodynamic scaling limit, we derive a description in terms of a large-scale universal kinetic equation. Our approach shows how the time-dependent generalized Gibbs ensemble assumption, which is often employed for treating low-dimensional nonequilibrium dissipative systems, emerges from systematic diagrammatics. It also allows us to exactly compute---for arbitrary spatial dimension---the decay exponent of the particle density. The latter is based on the large-scale description of the quantum dynamics and it differs from the mean-field prediction even in dimension larger than one. We moreover consider spatially inhomogeneous setups involving an external potential. In confined systems the density decay is accelerated towards the mean-field algebraic behavior, while for deconfined scenarios the power-law decay is replaced by a slower nonalgebraic decay.
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1862646656, FOR 5522: Quantenthermalisierung, Lokalisierung und eingeschränkte Dynamik mit wechselwirkenden ultrakalten Atomen, G2744928646, G3559029362, G3580386859, Nichtgleichgewichtsphasenübergänge in offenen Quantensystemen mit absorbierenden Zuständen, FOR 5413: Quantenspinsysteme mit langreichweitigen Wechselwirkungen: Experiment, Theorie und Mathematik, Novel non-equilibrium states of matter in periodically driven spin systems: from time crystals to integrated thermal machines, G6230771372, Understanding Quantum Non-Equilibrium Matter: Many-Body Localisation versus Glasses, Theory and Experiment
OpenAlex ID: W4399970619