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Explicit definition of PT symmetry for nonunitary quantum walks with gain and loss
| Title: | Explicit definition of PT symmetry for nonunitary quantum walks with gain and loss |
| Authors: | Mochizuki, Ken Browse this author | | Kim, Dakyeong Browse this author | | Obuse, Hideaki Browse this author →KAKEN DB |
| Keywords: | Nuclear spin | | Nuclear magnetic resonance | | Magnetic fields | | Polarization | | Magnetic field sensors |
| Issue Date: | 18-Jun-2016 |
| Publisher: | American Physical Society (APS) |
| Journal Title: | Physical Review A |
| Volume: | 93 |
| Issue: | 6 |
| Start Page: | 062116 |
| Publisher DOI: | 10.1103/PhysRevA.93.062116 |
| Abstract: | PT symmetry, that is, a combined parity and time-reversal symmetry, is a key milestone for non-Hermitian systems exhibiting entirely real eigenenergy. In the present work, motivated by a recent experiment, we study PT symmetry of the time-evolution operator of nonunitary quantum walks. We present the explicit definition of PT symmetry by employing a concept of symmetry time frames. We provide a necessary and sufficient condition so that the time-evolution operator of the nonunitary quantum walk retains PT symmetry even when parameters of the model depend on position. It is also shown that there exist extra symmetries embedded in the time-evolution operator. Applying these results, we clarify that the nonunitary quantum walk in the experiment does have PT symmetry. |
| Rights: | ©2016 American Physical Society |
| Type: | article |
| URI: | http://hdl.handle.net/2115/62592 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 小布施 秀明
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