Stabilizer entropies and nonstabilizerness monotones
- URL: http://arxiv.org/abs/2303.10152v2
- Date: Mon, 21 Aug 2023 08:29:26 GMT
- Title: Stabilizer entropies and nonstabilizerness monotones
- Authors: Tobias Haug, Lorenzo Piroli
- Abstract summary: We study different aspects of the stabilizer entropies (SEs)
We compare them against known nonstabilizerness monotones such as the min-relative entropy and the robustness of magic.
In addition to previously developed exact methods to compute the R'enyi SEs, we put forward a scheme based on perfect MPS sampling.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We study different aspects of the stabilizer entropies (SEs) and compare them
against known nonstabilizerness monotones such as the min-relative entropy and
the robustness of magic. First, by means of explicit examples, we show that,
for R\'enyi index $0\leq n<2$, the SEs are not monotones with respect to
stabilizer protocols which include computational-basis measurements, not even
when restricting to pure states (while the question remains open for $n\geq
2$). Next, we show that, for any R\'enyi index, the SEs do not satisfy a strong
monotonicity condition with respect to computational-basis measurements. We
further study SEs in different classes of many-body states. We compare the SEs
with other measures, either proving or providing numerical evidence for
inequalities between them. Finally, we discuss exact or efficient
tensor-network numerical methods to compute SEs of matrix-product states (MPSs)
for large numbers of qubits. In addition to previously developed exact methods
to compute the R\'enyi SEs, we also put forward a scheme based on perfect MPS
sampling, allowing us to compute efficiently the von Neumann SE for large bond
dimensions.
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