Emergent decoherence induced by quantum chaos in a many-body system: A Loschmidt echo observation through NMR

ANA K. CHATTAH

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

AMER PHYSICAL SOC

Año: 2022 vol. 105

1050-2947

n the long quest to identify and compensate the sources of decoherence in many-body systems far from the ground state, the varied family of Loschmidt echoes (LEs) became an invaluable tool in several experimental techniques. A LE involves a time-reversal procedure to assess the effect of perturbations in a quantum excitation dynamics. However, when addressing macroscopic systems one is repeatedly confronted with limitations that seem insurmountable. This led to the formulation of the central hypothesis of irreversibility stating that the timescale of decoherence, is proportional to the timescale of the many-body interactions we reverse. We test this by implementing two experimental schemes based on Floquet Hamiltonians where the effective strength of the dipolar spin-spin coupling,is reduced by a variable scale factor . Strikingly, we observe the superposition of the normalized Loschmidt echoes. This manifests the dominance of the intrinsic dynamics over the perturbation factors, eve