Local PT symmetry violates the no-signaling principle

Yi-Chan Lee; Min-Hsiu Hsieh; Steven T Flammia; Ray-Kuang Lee

doi:10.1103/PhysRevLett.112.130404

Local PT symmetry violates the no-signaling principle

Phys Rev Lett. 2014 Apr 4;112(13):130404. doi: 10.1103/PhysRevLett.112.130404. Epub 2014 Apr 3.

Authors

Yi-Chan Lee¹, Min-Hsiu Hsieh², Steven T Flammia³, Ray-Kuang Lee⁴

Affiliations

¹ Physics Department, National Tsing-Hua University, Hsinchu City 300, Taiwan and Centre for Quantum Computation & Intelligent Systems, Faculty of Engineering and Information Technology, University of Technology, Sydney, New South Wales 2007, Australia.
² Centre for Quantum Computation & Intelligent Systems, Faculty of Engineering and Information Technology, University of Technology, Sydney, New South Wales 2007, Australia.
³ School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.
⁴ Physics Department, National Tsing-Hua University, Hsinchu City 300, Taiwan and Institute of Photonics Technologies, National Tsing-Hua University, Hsinchu City 300, Taiwan.

PMID: 24745396
DOI: 10.1103/PhysRevLett.112.130404

Abstract

Bender et al. [Phys. Rev. Lett. 80, 5243 (1998)] have developed PT-symmetric quantum theory as an extension of quantum theory to non-Hermitian Hamiltonians. We show that when this model has a local PT symmetry acting on composite systems, it violates the nonsignaling principle of relativity. Since the case of global PT symmetry is known to reduce to standard quantum mechanics A. Mostafazadeh [J. Math. Phys. 43, 205 (2001)], this shows that the PT-symmetric theory is either a trivial extension or likely false as a fundamental theory.