Unavoidable decoherence in the quantum control of
an unknown state

• Authors: D. Kielpinski , R.A. Briggs , H.M. Wiseman
• Languages of publication: EN

Abstracts

EN

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.

Keywords

EN

quantum decoherence; quantum measurement; quantum control; decoherence-free subspace

• Publisher: Versita
• Journal: Quantum Measurements and Quantum Metrology
• Year: 2013
• Volume: 1
• Pages: 1-4

Dates

online

06 - 02 - 2013

accepted

16 - 1 - 2013

received

29 - 11 - 2012

Contributors

author

D. Kielpinski

• Centre for Quantum Dynamics, Griffith University,
  Nathan QLD 4111, Australia
• School of Biomolecular and Physical Sciences, Griffith University,
  Nathan QLD 4111, Australia

author

R.A. Briggs

• School of Biomolecular and Physical Sciences, Griffith University,
  Nathan QLD 4111, Australia
• School of Philosophy, Australian National University,
  Canberra ACT 0200, Australia

author

H.M. Wiseman

• Centre for Quantum Dynamics, Griffith University,
  Nathan QLD 4111, Australia
• School of Biomolecular and Physical Sciences, Griffith University,
  Nathan QLD 4111, Australia
• ARC Centre of Excellence for Quantum Computation and
  Communication Technology, Griffith University,
  Nathan QLD 4111, Australia

References

• H. M. Wiseman and G. J. Milburn, Quantum Measurementand Control (Cambridge University Press,Cambridge, UK, 2010).
• K. Khodjasteh, D. A. Lidar, and L. Viola, Phys. Rev.Lett. 104, 090501 (2010).[Crossref]
• J. Kerckhoff, H. I. Nurdin, D. S. Pavlichin, andH. Mabuchi, Phys. Rev. Lett. 105, 040502 (2010).[Crossref]
• M. F. Santos, M. Terra Cunha, R. Chaves, and A. R. R.Carvalho, Phys. Rev. Lett. 108, 170501 (2012).[Crossref]
• R. Vijay, C. Macklin, D. H. Slichter, S. J. Weber, K. W.Murch, R. Naik, A. N. Korotkov, and I. Siddiqi, Nature490, 77 (2012).
• G. Xiang, B. Higgins, D. Berry, H. Wiseman, andG. Pryde, Nature Photonics 5, 43 (2010).
• H. Yonezawa, D. Nakane, T. A. Wheatley, K. Iwasawa,S. Takeda, H. Arao, K. Ohki, K. Tsumura, D. W. Berry,T. C. Ralph, et al., Science 337, 1514 (2012).
• C. Sayrin, I. Dotsenko, X. Zhou, B. Peaudecerf,T. Rybarczyk, S. Gleyzes, P. Rouchon, M. Mirrahimi,H. Amini, M. Brune, et al., Nature 477, 73 (2011).
• L. M. Norris, C. M. Trail, P. S. Jessen, and I. H.Deutsch, Phys. Rev. Lett. 109, 173603 (2012).[Crossref]
• R. I. Karasik and H. M. Wiseman, Phys. Rev. Lett.106, 020406 (2011).[Crossref]
• M. Roth, L. Guyon, J. Roslund, V. Boutou, F. Courvoisier,J.-P. Wolf, and H. Rabitz, Phys. Rev. Lett. 102,253001 (2009).
• H. M. Wiseman and G. J. Milburn, Phys. Rev. A 49,4110 (1994).
• S. Lloyd, Phys. Rev. A 62, 022108 (2000).
• P. Zanardi and M. Rasetti, Phys. Rev. Lett. 79, 3306(1997).
• D. Lidar, I. Chuang, and K. Whaley, Phys. Rev. Lett.81, 2594 (1998).
• J. Pearl, Causality: Models, Reasoning, and Inference(Cambridge University Press, 2000).
• B. Skyrms, Causal Necessity (Yale University Press,1980), chap. IIC. The Role of Causal Factors in RationalDecision, pp. 128–139.
• A. Gibbard, in Ifs: Conditionals, Belief, Decision,Chance, and Time, edited by S. R. Harper, W. L. andG. Pearce (D. Reidel, Dordrecht, 1980).
• R. Stalnaker, in Studies in Logical Theory (Blackwell,Oxford, 1968), vol. 2 of American PhilosophicalQuarterly Monograph Series.
• S. Bolognani and F. Ticozzi, IEEE Trans. Autom. Control55, 2721 (2010).
• G. Milburn, Philos. Trans. R. Soc. A 370, 4469 (2012).

Identifiers

DOI

10.2478/qmetro-2013-0001