Pith. sign in

REVIEW 6 cited by

Measuring the quality of a quantum reference frame: the relative entropy of frameness

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 0901.0943 v2 pith:ZFOPH4HP submitted 2009-01-07 quant-ph

classification quant-ph
keywords entropyrelativeframereferencetokenframenessentanglementgroup
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
read the original abstract

In the absence of a reference frame for transformations associated with a group G, any quantum state that is non-invariant under the action of G may serve as a token of the missing reference frame. We here introduce a novel measure of the quality of such a token: the relative entropy of frameness. This is defined as the relative entropy distance between the state of interest and the nearest G-invariant state. Unlike the relative entropy of entanglement, this quantity is straightforward to calculate and we find it to be precisely equal to the G-asymmetry, a measure of frameness introduced by Vaccaro et al. It is shown to provide an upper bound on the mutual information between the group element encoded into the token and the group element that may be extracted from it by measurement. In this sense, it quantifies the extent to which the token successfully simulates a full reference frame. We also show, that despite a suggestive analogy from entanglement theory, the regularized relative entropy of frameness is zero and therefore does not quantify the rate of interconversion between the token and some standard form of quantum reference frame. Finally, we show how these investigations yield a novel approach to bounding the relative entropy of entanglement.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Boundary quenches in (1+1)-dimensional conformal field theory

    cond-mat.stat-mech 2026-07 accept novelty 7.0 of 10

    A boundary quench in a (1+1)-d CFT makes one-point functions switch from old to new ground state across a light cone and makes adjacent-region entanglement jump by log(g_b/g_a).

  2. Resource-Theoretic Quantifiers of Weak and Strong Symmetry Breaking: Strong Entanglement Asymmetry and Beyond

    hep-th 2026-01 unverdicted novelty 7.0 of 10

    A resource theory for strong symmetry breaking is formulated, with the variance of the conserved quantity characterizing its asymptotic manipulation for U(1) symmetry and enabling tracking of weak-to-strong conversion...

  3. Entanglement asymmetry in CFT with boundary symmetry breaking

    hep-th 2024-11 conditional novelty 6.0 of 10

    For a (1+1)-dimensional CFT with a symmetry-breaking boundary, the entanglement asymmetry of an interval anchored at the boundary tends to log|G| with an algebraic correction whose exponent is twice the smallest bound...

  4. Entanglement asymmetry and symmetry defects in boundary conformal field theory

    hep-th 2024-11 conditional novelty 6.0 of 10

    For 2D CFTs with boundary-only symmetry breaking, the entanglement asymmetry is log|G| with power-law corrections for finite groups, (dim G/2) log log(ℓ/ε) for compact Lie groups, and it drops from log|G| to 0 at t=ℓ/...

  5. Specifying the operational meaning of quantum reference frames

    quant-ph 2026-07 conditional novelty 5.0 of 10

    Position-superposed labs define quantum reference frames operationally, differ from Wigner's-friend observers, and can broadcast outcomes without decohering their position superposition.

  6. What can we do in a symmetry-constrained perspective? The importance of the total charge's status in quantum reference frame frameworks

    quant-ph 2025-10 conditional novelty 5.0 of 10

    A two-observer Z2 toy model is used to argue that internal observers can access the total charge, favoring weak over strong symmetry in quantum reference frame frameworks.

Pith tools