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Digital quantum simulation of open quantum systems using quantum imaginary time evolution

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 Added by Hirsh Kamakari
 Publication date 2021
  fields Physics
and research's language is English




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Quantum simulation on emerging quantum hardware is a topic of intense interest. While many studies focus on computing ground state properties or simulating unitary dynamics of closed systems, open quantum systems are an interesting target of study owing to their ubiquity and rich physical behavior. However, their non-unitary dynamics are also not natural to simulate on near-term quantum hardware. Here, we report algorithms for the digital quantum simulation of the dynamics of open quantum systems governed by a Lindblad equation using an adaptation of the quantum imaginary time evolution (QITE) algorithm. We demonstrate the algorithms on IBM Quantums hardware with simulations of the spontaneous emission of a two level system and the dissipative transverse field Ising model. Our work shows that the dynamics of open quantum systems can be efficiently simulated on near-term quantum hardware.



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Non-Markovian reduced dynamics of an open system is investigated. In the case the initial state of the reservoir is the vacuum state, an approximation is introduced which makes possible to construct a reduced dynamics which is completely positive.
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