690 research outputs found
Irreversibility in asymptotic manipulations of entanglement
We show that the process of entanglement distillation is irreversible by
showing that the entanglement cost of a bound entangled state is finite. Such
irreversibility remains even if extra pure entanglement is loaned to assist the
distillation process.Comment: RevTex, 3 pages, no figures Result on indistillability of PPT states
under pure entanglement catalytic LOCC adde
Three Approaches to the Greater Inclusion of Women in Public Worship
In the spring of 2022, elders and ministers from three West Texas Churches of Christ convened for a discussion of how their congregations expanded the roles of women in public worship. Tradition within the Churches of Christ dictate that men fill all visible roles during worship services. Since these practices are based in commonly accepted interpretations of the scripture, women’s active participation in worship represents a momentous change in both practice and belief. The ninety-minute discussion covered the initial decision-making process, the implementation of new roles, problems encountered, and advice for others wanting to make a similar change. The transcript has been edited for clarity, but otherwise is an exact account of the discussion as the church leaders reflected on their experiences
Oneness in Christ: A Qualitative Study of Women’s Initial Experiences Leading in Public Worship at Broadway Church of Christ
Few Church of Christ women have had experience with taking an active leadership role in a worship service since these congregations have traditionally believed women leading worship is unscriptural. Recently more Churches of Christ have begun to change their understanding of scripture in ways that are more inclusive of women. In March 2019, after a six-month church wide bible study at the historic Broadway Church of Christ in Lubbock, TX, women took on public roles in a worship service in what was for most of them the first time to serve in front of a congregation.
To document their experiences, the researchers conducted interviews with thirty-two women who participated in a leading worship role during the first year of this change. Participants described their evolving beliefs about women’s roles in worship; their experience as they participated in worship; meanings they assigned to their participation; and how their changing roles affected their experience of worship and community at Broadway
Distributed Entanglement
Consider three qubits A, B, and C which may be entangled with each other. We
show that there is a trade-off between A's entanglement with B and its
entanglement with C. This relation is expressed in terms of a measure of
entanglement called the "tangle," which is related to the entanglement of
formation. Specifically, we show that the tangle between A and B, plus the
tangle between A and C, cannot be greater than the tangle between A and the
pair BC. This inequality is as strong as it could be, in the sense that for any
values of the tangles satisfying the corresponding equality, one can find a
quantum state consistent with those values. Further exploration of this result
leads to a definition of the "three-way tangle" of the system, which is
invariant under permutations of the qubits.Comment: 13 pages LaTeX; references added, derivation of Eq. (11) simplifie
Low-complexity quantum codes designed via codeword-stabilized framework
We consider design of the quantum stabilizer codes via a two-step,
low-complexity approach based on the framework of codeword-stabilized (CWS)
codes. In this framework, each quantum CWS code can be specified by a graph and
a binary code. For codes that can be obtained from a given graph, we give
several upper bounds on the distance of a generic (additive or non-additive)
CWS code, and the lower Gilbert-Varshamov bound for the existence of additive
CWS codes. We also consider additive cyclic CWS codes and show that these codes
correspond to a previously unexplored class of single-generator cyclic
stabilizer codes. We present several families of simple stabilizer codes with
relatively good parameters.Comment: 12 pages, 3 figures, 1 tabl
Pauli Exchange Errors in Quantum Computation
In many physically realistic models of quantum computation, Pauli exchange
interactions cause a subset of two-qubit errors to occur as a first order
effect of couplings within the computer, even in the absence of interactions
with the computer's environment. We give an explicit 9-qubit code that corrects
both Pauli exchange errors and all one-qubit errors.Comment: Final version accepted for publication in Phys. Rev. Let
Local permutations of products of Bell states and entanglement distillation
We present new algorithms for mixed-state multi-copy entanglement
distillation for pairs of qubits. Our algorithms perform significantly better
than the best known algorithms. Better algorithms can be derived that are tuned
for specific initial states. The new algorithms are based on a characterization
of the group of all locally realizable permutations of the 4^n possible tensor
products of n Bell states.Comment: 6 pages, 1 figur
On the Form Factor for the Unitary Group
We study the combinatorics of the contributions to the form factor of the
group U(N) in the large limit. This relates to questions about
semiclassical contributions to the form factor of quantum systems described by
the unitary ensemble.Comment: 35 page
From Skew-Cyclic Codes to Asymmetric Quantum Codes
We introduce an additive but not -linear map from
to and exhibit some of its interesting
structural properties. If is a linear -code, then is an
additive -code. If is an additive cyclic code then
is an additive quasi-cyclic code of index . Moreover, if is a module
-cyclic code, a recently introduced type of code which will be
explained below, then is equivalent to an additive cyclic code if is
odd and to an additive quasi-cyclic code of index if is even. Given any
-code , the code is self-orthogonal under the trace
Hermitian inner product. Since the mapping preserves nestedness, it can be
used as a tool in constructing additive asymmetric quantum codes.Comment: 16 pages, 3 tables, submitted to Advances in Mathematics of
Communication
Increasing subsequences and the hard-to-soft edge transition in matrix ensembles
Our interest is in the cumulative probabilities Pr(L(t) \le l) for the
maximum length of increasing subsequences in Poissonized ensembles of random
permutations, random fixed point free involutions and reversed random fixed
point free involutions. It is shown that these probabilities are equal to the
hard edge gap probability for matrix ensembles with unitary, orthogonal and
symplectic symmetry respectively. The gap probabilities can be written as a sum
over correlations for certain determinantal point processes. From these
expressions a proof can be given that the limiting form of Pr(L(t) \le l) in
the three cases is equal to the soft edge gap probability for matrix ensembles
with unitary, orthogonal and symplectic symmetry respectively, thereby
reclaiming theorems due to Baik-Deift-Johansson and Baik-Rains.Comment: LaTeX, 19 page
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