Quantum reaction-limited reaction-diffusion dynamics of annihilation processes

Area of Science:

• Quantum physics
• Condensed matter physics
• Statistical mechanics

Background:

• Classical reaction-diffusion systems exhibit power-law density decay.
• Spatial correlations and diffusive mixing influence classical decay exponents.
• Mean-field theory applies in strong diffusive mixing (reaction-limited) regimes for classical particles.

Purpose of the Study:

• Investigate quantum reaction-diffusion dynamics of fermionic particles.
• Analyze annihilation reactions (2A→∅, 3A→∅, 4A→∅) in a quantum context.
• Compare quantum behavior to classical predictions, focusing on the reaction-limited regime.

Main Methods:

• Modeling quantum fermionic particles with coherent hopping in a 1D lattice.
• Simulating dissipative annihilation processes (pairs, triplets, quadruplets).
• Analyzing quantum reaction-limited dynamics and emergent power-law behaviors.

Main Results:

• Quantum systems show power-law decay beyond mean-field for all three annihilation processes.
• This quantum effect stems from quantum coherences, independent of spatial dimensionality.
• 3A→∅ exhibits intricate behavior: power-law decay in an intermediate window, then non-power-law decay.

Conclusions:

• Quantum coherences fundamentally alter reaction-diffusion dynamics compared to classical systems.
• Emergent critical behavior in quantum systems originates from quantum coherences, not spatial correlations.
• The findings highlight distinct mechanisms driving critical phenomena in quantum versus classical physics.