On the definition of entanglement entropy in lattice gauge theories
Abstract
We focus on the issue of proper definition of entanglement entropy in lattice gauge theories, and examine a naive definition where gauge invariant states are viewed as elements of an extended Hilbert space which contains gauge non-invariant states as well. Working in the extended Hilbert space, we can define entanglement entropy associated with an arbitrary subset of links, not only for abelian but also for non-abelian theories. We then derive the associated replica formula. We also discuss the issue of gauge invariance of the entanglement entropy. In the Z N gauge theories in arbitrary space dimensions, we show that all the standard properties of the entanglement entropy, e.g. the strong subadditivity, hold in our definition. We study the entanglement entropy for special states, including the topological states for the Z N gauge theories in arbitrary dimensions. We discuss relations of our definition to other proposals.
- Publication:
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Journal of High Energy Physics
- Pub Date:
- June 2015
- DOI:
- 10.1007/JHEP06(2015)187
- arXiv:
- arXiv:1502.04267
- Bibcode:
- 2015JHEP...06..187A
- Keywords:
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- Lattice Gauge Field Theories;
- Gauge Symmetry;
- High Energy Physics - Theory;
- High Energy Physics - Lattice;
- Quantum Physics
- E-Print:
- 29 pages, 1 figure, a comment and more references added, some typos corrected