Tampere University of Technology

TUTCRIS Research Portal

Observation of PT-symmetric quantum interference

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
JournalNature Photonics
DOIs
Publication statusPublished - 16 Sep 2019
Publication typeA1 Journal article-refereed

Abstract

A common wisdom in quantum mechanics is that the Hamiltonian has to be Hermitian in order to ensure a real eigenvalue spectrum. Yet, parity–time (PT)-symmetric Hamiltonians are sufficient for real eigenvalues and therefore constitute a complex extension of quantum mechanics beyond the constraints of Hermiticity. However, as only single-particle or classical wave physics has been exploited so far, an experimental demonstration of the true quantum nature of PT symmetry has been elusive. In our work, we demonstrate two-particle quantum interference in a PT-symmetric system. We employ integrated photonic waveguides to reveal that the quantum dynamics of indistinguishable photons shows strongly counterintuitive features. To substantiate our experimental data, we analytically solve the quantum master equation using Lie algebra methods. The ideas and results presented here pave the way for non-local PT-symmetric quantum mechanics as a novel building block for future quantum devices.

Publication forum classification

Field of science, Statistics Finland