Square Root Statistics of Density Matrices and Their Applications
To estimate the degree of quantum entanglement of random pure states, it is crucial to understand the statistical behavior of entanglement indicators such as the von Neumann entropy, quantum purity, and entanglement capacity. These entanglement metrics are functions of the spectrum of density matrices, and their statistical behavior over different generic state ensembles have been intensively studied in the literature. As an alternative metric, in this work, we study the sum of the square root spectrum of density matrices, which is relevant to negativity and fidelity in quantum information processing. In particular, we derive the finite-size mean and variance formulas of the sum of the square root spectrum over the Bures–Hall ensemble, extending known results obtained recently over the Hilbert–Schmidt ensemble.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States); Texas Tech University, Lubbock, TX (United States)
- Sponsoring Organization:
- USDOE; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
- Grant/Contract Number:
- AC02-06CH11357; SC0024631
- OSTI ID:
- 2281038
- Alternate ID(s):
- OSTI ID: 2337761
OSTI ID: 2474887
- Journal Information:
- Entropy, Journal Name: Entropy Journal Issue: 1 Vol. 26; ISSN ENTRFG; ISSN 1099-4300
- Publisher:
- MDPI AGCopyright Statement
- Country of Publication:
- Switzerland
- Language:
- English