Description
Non-Markovian effects are often significant when the system-environment coupling is not weak. We show that, within the framework of pure dephasing, the non-Markovianity displayed by a two-level system (TLS) can, in fact, be far more pronounced. To demonstrate that this is indeed the case, we consider a pure dephasing model where a collection of TLSs interacts with a common environment. We obtain the dynamics of the collection of the TLSs and then take a partial trace over all the TLSs except one. This remaining TLS exhibits markedly non-Markovian dynamics, even when the system-environment coupling is weak. This is due to the environment-mediated indirect interaction between the TLSs. In fact, this indirect interaction can not only substantially increase the non-Markovianity but also qualitatively change the characteristics of the non-Markovian behavior. For instance, for a single TLS undergoing pure dephasing, the dynamics are Markovian for both Ohmic and sub-Ohmic environments. This is markedly not the case when we consider multiple TLSs. These findings provide insights into controlling decoherence in multi-qubit quantum systems and have implications for quantum technologies where non-Markovianity can be a resource rather than a limitation.
| I am the presenting author | Yes |
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