Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Optical control of the complex phase of a quantum ground-state amplitude

Kinos, Adam LU ; Dalgaard, Mogens and Mølmer, Klaus (2022) In Physical Review A 105(6).
Abstract

We discuss how coherent driving of a two-level quantum system can be used to induce a complex phase on the ground state and we discuss its geometric and dynamic contributions. While the global phase of a wave function has no physical significance, the coherent dynamics in a two-level subspace provides relative phases and is an essential building block for more advanced dynamics in larger systems. In this regard, we note that one must be careful with intuitive accounts of the phase dynamics as it depends on the interaction picture applied. To mitigate ambiguities in practical analyses, we suggest to complement the Bloch sphere picture with the path taken by the ground-state amplitude in the complex plane, and we show how the two-level... (More)

We discuss how coherent driving of a two-level quantum system can be used to induce a complex phase on the ground state and we discuss its geometric and dynamic contributions. While the global phase of a wave function has no physical significance, the coherent dynamics in a two-level subspace provides relative phases and is an essential building block for more advanced dynamics in larger systems. In this regard, we note that one must be careful with intuitive accounts of the phase dynamics as it depends on the interaction picture applied. To mitigate ambiguities in practical analyses, we suggest to complement the Bloch sphere picture with the path taken by the ground-state amplitude in the complex plane, and we show how the two-level pure-state dynamics can serve as a starting point for the study of the dynamics explored in three-level lambda systems, four-level tripod systems, and open quantum systems.

(Less)
Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review A
volume
105
issue
6
article number
062441
pages
12 pages
publisher
American Physical Society
external identifiers
  • scopus:85133383303
ISSN
2469-9926
DOI
10.1103/PhysRevA.105.062441
language
English
LU publication?
yes
additional info
Funding Information: This research was supported by the Danish National Research Foundation (Grant No. DNRF156) and has received funding from the European Union's Horizon 2020 research and innovation program under Grants No. 820391 (SQUARE) and No. 754513 (Marie Sklodowska-Curie program). Publisher Copyright: © 2022 authors. Published by the American Physical Society.
id
54ad3349-d9a4-4847-ab18-46efa960d88a
date added to LUP
2022-08-19 08:52:38
date last changed
2023-11-21 02:23:29
@article{54ad3349-d9a4-4847-ab18-46efa960d88a,
  abstract     = {{<p>We discuss how coherent driving of a two-level quantum system can be used to induce a complex phase on the ground state and we discuss its geometric and dynamic contributions. While the global phase of a wave function has no physical significance, the coherent dynamics in a two-level subspace provides relative phases and is an essential building block for more advanced dynamics in larger systems. In this regard, we note that one must be careful with intuitive accounts of the phase dynamics as it depends on the interaction picture applied. To mitigate ambiguities in practical analyses, we suggest to complement the Bloch sphere picture with the path taken by the ground-state amplitude in the complex plane, and we show how the two-level pure-state dynamics can serve as a starting point for the study of the dynamics explored in three-level lambda systems, four-level tripod systems, and open quantum systems.</p>}},
  author       = {{Kinos, Adam and Dalgaard, Mogens and Mølmer, Klaus}},
  issn         = {{2469-9926}},
  language     = {{eng}},
  number       = {{6}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review A}},
  title        = {{Optical control of the complex phase of a quantum ground-state amplitude}},
  url          = {{http://dx.doi.org/10.1103/PhysRevA.105.062441}},
  doi          = {{10.1103/PhysRevA.105.062441}},
  volume       = {{105}},
  year         = {{2022}},
}