Imperial College London
Alternate

DrDavidJennings

Faculty of Natural Sciences, Department of Physics

Research Associate
 
 
 
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Contact

 

+44 (0)20 7594 0971d.jennings Website

 
 
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Location

 

Electrical EngineeringSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jennings:2020:10.1103/PhysRevX.10.041035,
author = {Jennings, D and Cirstoiu, C and Korzekwa, K},
doi = {10.1103/PhysRevX.10.041035},
journal = {Physical Review X},
pages = {041035  1--041035  41},
title = {Robustness of Noether's principle: maximal disconnects between conservation laws and symmetries in quantum theory},
url = {http://dx.doi.org/10.1103/PhysRevX.10.041035},
volume = {10},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - To what extent does Noether’s principle apply to quantum channels? Here, we quantify the degreeto which imposing a symmetry constraint on quantum channels implies a conservation law, and showthat this relates to physically impossible transformations in quantum theory, such as time-reversaland spin-inversion. In this analysis, the convex structure and extremal points of the set of quantumchannels symmetric under the action of a Lie group G becomes essential. It allows us to derivebounds on the deviation from conservation laws under any symmetric quantum channel in terms ofthe deviation from closed dynamics as measured by the unitarity of the channel E. In particular,we investigate in detail the U(1) and SU(2) symmetries related to energy and angular momentumconservation laws. In the latter case, we provide fundamental limits on how much a spin-jA systemcan be used to polarise a larger spin-jB system, and on how much one can invert spin polarisationusing a rotationally-symmetric operation. Finally, we also establish novel links between unitarity,complementary channels and purity that are of independent interest.
AU  - Jennings,D
AU  - Cirstoiu,C
AU  - Korzekwa,K
DO  - 10.1103/PhysRevX.10.041035
EP  - 1
PY  - 2020///
SN  - 2160-3308
SP  - 041035
TI  - Robustness of Noether's principle: maximal disconnects between conservation laws and symmetries in quantum theory
T2  - Physical Review X
UR  - http://dx.doi.org/10.1103/PhysRevX.10.041035
UR  - https://journals.aps.org/prx/abstract/10.1103/PhysRevX.10.041035
UR  - http://hdl.handle.net/10044/1/82557
VL  - 10
ER  -
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