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Unavoidable decoherence in the quantum control of an unknown state
- Source :
- Quantum Measurements and Quantum Metrology, Vol 1, Iss 1, Pp 1-4 (2013)
- Publication Year :
- 2013
- Publisher :
- arXiv, 2013.
-
Abstract
- A common objective for quantum control is to force a quantum system, initially in an unknown state, into a particular target subspace. We show that if the subspace is required to be a decoherence-free subspace of dimension greater than 1, then such control must be decoherent. That is, it will take almost any pure state to a mixed state. We make no assumptions about the control mechanism, but our result implies that for this purpose coherent control offers no advantage, in principle, over the obvious measurement-based feedback protocol.<br />Comment: 3 pages. To be published in Quantum Measurements & Quantum Metrology http://versita.com/qm/
- Subjects :
- Quantum Physics
Technology
Quantum decoherence
Computer science
quantum measurement
FOS: Physical sciences
State (functional analysis)
decoherence-free subspace
Dimension (vector space)
Control theory
Coherent control
quantum decoherence
Quantum system
Control (linguistics)
quantum control
Quantum Physics (quant-ph)
Protocol (object-oriented programming)
Subspace topology
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- Quantum Measurements and Quantum Metrology, Vol 1, Iss 1, Pp 1-4 (2013)
- Accession number :
- edsair.doi.dedup.....0becaf36c67a77e5f6a13bffce09e220
- Full Text :
- https://doi.org/10.48550/arxiv.1302.0037