logo

Operational effects of the UNOT gate on classical and quantum correlations

More info
  • ReceivedMar 29, 2018
  • AcceptedMay 8, 2018
  • PublishedMay 18, 2018

Abstract

The NOT gate that flips a classical bit is ubiquitous in classical information processing. However its quantum analogue, the universal NOT (UNOT) gate that flips a quantum spin in any alignment into its antipodal counterpart is strictly forbidden. Here we explore the connection between this discrepancy and how UNOT gates affect classical and quantum correlations. We show that while a UNOT gate always preserves classical correlations between two spins, it can non-locally increase or decrease their shared discord in ways that allow violation of the data processing inequality. We experimentally illustrate this using a multi-level trapped 171Yb+ ion that allows simulation of anti-unitary operations.


References

[1] N. Gisin, S. PopescuSpin flips and quantum information for antiparallel spins. Phys Rev Lett, 83 (1999), p. 432. CrossRef Google Scholar

[2] H. Bechmann-Pasquinucci, N. GisinIncoherent and coherent eavesdropping in the six-state protocol of quantum cryptography. Phys Rev A, 59 (1999), p. 4238. CrossRef Google Scholar

[3] V. Buek, M. Hillery, R.F. WernerOptimal manipulations with qubits: universal-not gate. Phys Rev A, 60 (1999), p. R2626. Google Scholar

[4] U. Alvarez-Rodriguez, M. Sanz, L. Lamata, et al.The forbidden quantum adder. Sci Rep, 5 (2015), p. 11983. Google Scholar

[5] F. De Martini, V. Bužek, F. Sciarrino, et al.Experimental realization of the quantum universal not gate. Nature, 419 (2002), p. 815. CrossRef Google Scholar

[6] M. Ricci, F. Sciarrino, C. Sias, et al.Teleportation scheme implementing the universal optimal quantum cloning machine and the universal not gate. Phys Rev Lett, 92 (2004). Google Scholar

[7] V. Scarani, S. Iblisdir, N. Gisin, et al.Quantum cloning. Rev Mod Phys, 77 (2005), p. 1225. CrossRef Google Scholar

[8] H. Ollivier, W.H. ZurekQuantum discord: a measure of the quantumness of correlations. Phys Rev Lett, 88 (2001). Google Scholar

[9] L. Henderson, V. VedralClassical, quantum and total correlations. J Phys A Math Gen, 34 (2001), p. 6899. CrossRef Google Scholar

Copyright 2020 Science China Press Co., Ltd. 《中国科学》杂志社有限责任公司 版权所有

京ICP备17057255号       京公网安备11010102003388号