18th SmoleQ Greeting Seminar (2026.4.23 at 16:00 (JST))

 

Speaker: 

Alberto Ferrara 

Title: 

Tunneling of bosonic qubits under local dephasing through microscopic approach

Abstract:

We present a microscopic derivation of a master equation for two-component bosons which tunnel between spatially separated modes under local dephasing noise. Starting from the full system-bath Hamiltonian with Lorentzian coupling distributions, we analytically obtain a time-local master equation whose structure reveals intrinsic non-Markovian features and recovers the standard phenomenological dephasing model in the short-time limit. We identify a resonance condition between tunneling and bath frequencies for which dephasing drives the system towards correlated steady states, stabilizing coherence and entanglement instead of suppressing them. Comparison with exact pseudomode simulations confirms the validity of the master equation beyond weak-coupling and Markovian regimes and allows us to describe the physical mechanism for the stabilization of coherent oscillations. These results establish a microscopic foundation for dephasing models in bosonic tunneling systems and reveal a noise-induced mechanism for steady-state entanglement of identical particles.