Emergent decoherence induced by quantum chaos in a many-body system: A
Loschmidt echo observation through NMR
- URL: http://arxiv.org/abs/2112.00607v1
- Date: Wed, 1 Dec 2021 16:22:43 GMT
- Title: Emergent decoherence induced by quantum chaos in a many-body system: A
Loschmidt echo observation through NMR
- Authors: Claudia M. S\'anchez, Ana Karina Chattah, and Horacio M. Pastawski
- Abstract summary: We show that the time-scale of decoherence, $T_3$, is proportional to the time-scale of many-body interactions we reversed, $T$ 0.01.
Strikingly, we observe the superposition of the normalized Loschmidt echoes for the bigger values $k$.
Results support the central hypothesis of irreversibility.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: In 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
formulate the \textit{central hypothesis of irreversibility} stating that the
time-scale of decoherence, $T_3$, is proportional to the time-scale of the
many-body interactions we reversed, $T_2$. We test this by implementing two
experimental schemes based on Floquet Hamiltonians where the effective strength
of the dipolar spin-spin coupling, i.e. $1/T_2$, is reduced by a variable scale
factor $k$. This extends the perturbations time scale, $T_\Sigma$, in relation
to $T_2$. Strikingly, we observe the superposition of the normalized Loschmidt
echoes for the bigger values of $k$. This manifests the dominance of the
intrinsic dynamics over the perturbation factors, even when the Loschmidt echo
is devised to reverse that intrinsic dynamics. Thus, in the limit where the
reversible interactions dominate over perturbations, the LE decays within a
time-scale, $T_3\approx T_2/R$ with $R=(0.15 \pm 0.01)$, confirming the
emergence of a perturbation independent regime. These results support the
central hypothesis of irreversibility.
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