Eternal non-Markovianity: from random unitary to Markov chain realisations
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
The theoretical description of quantum dynamics in an intriguing way does not necessarily imply
the underlying dynamics is indeed intriguing. Here we show how a known very interesting master
equation with an always negative decay rate [eternal non-Markovianity (ENM)] arises from simple
stochastic Schrödinger dynamics (random unitary dynamics). Equivalently, it may be seen as arising
from a mixture of Markov (semi-group) open system dynamics. Both these approaches lead to a more
general family of CPT maps, characterized by a point within a parameter triangle. Our results show
how ENM quantum dynamics can be realised easily in the laboratory. Moreover, we find a quantum
time-continuously measured (quantum trajectory) realisation of the dynamics of the ENM master
equation based on unitary transformations and projective measurements in an extended Hilbert space,
guided by a classical Markov process. Furthermore, a Gorini-Kossakowski-Sudarshan-Lindblad (GKSL)
representation of the dynamics in an extended Hilbert space can be found, with a remarkable property:
there is no dynamics in the ancilla state. Finally, analogous constructions for two qubits extend these
results from non-CP-divisible to non-P-divisible dynamics.
the underlying dynamics is indeed intriguing. Here we show how a known very interesting master
equation with an always negative decay rate [eternal non-Markovianity (ENM)] arises from simple
stochastic Schrödinger dynamics (random unitary dynamics). Equivalently, it may be seen as arising
from a mixture of Markov (semi-group) open system dynamics. Both these approaches lead to a more
general family of CPT maps, characterized by a point within a parameter triangle. Our results show
how ENM quantum dynamics can be realised easily in the laboratory. Moreover, we find a quantum
time-continuously measured (quantum trajectory) realisation of the dynamics of the ENM master
equation based on unitary transformations and projective measurements in an extended Hilbert space,
guided by a classical Markov process. Furthermore, a Gorini-Kossakowski-Sudarshan-Lindblad (GKSL)
representation of the dynamics in an extended Hilbert space can be found, with a remarkable property:
there is no dynamics in the ancilla state. Finally, analogous constructions for two qubits extend these
results from non-CP-divisible to non-P-divisible dynamics.
Details
Original language | English |
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Number of pages | 11 |
Journal | Scientific Reports |
Publication status | Published - 2017 |
Peer-reviewed | Yes |
External IDs
Scopus | 85026208528 |
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ORCID | /0000-0002-7806-3525/work/142234157 |
Keywords
Keywords
- non-Markovianity, quantum dynamics, master equation, Markov Process