2,076 research outputs found
Ordered Measurements of Permutationally-Symmetric Qubit Strings
We show that any sequence of measurements on a permutationally-symmetric
(pure or mixed) multi-qubit string leaves the unmeasured qubit substring also
permutationally-symmetric. In addition, we show that the measurement
probabilities for an arbitrary sequence of single-qubit measurements are
independent of how many unmeasured qubits have been lost prior to the
measurement. Our results are valuable for quantum information processing of
indistinguishable particles by post-selection, e.g. in cases where the results
of an experiment are discarded conditioned upon the occurrence of a given event
such as particle loss. Furthermore, our results are important for the design of
adaptive-measurement strategies, e.g. a series of measurements where for each
measurement instance, the measurement basis is chosen depending on prior
measurement results.Comment: 13 page
Boundary-induced violation of the Dirac fermion parity and its signatures in local and global tunneling spectra of graphene
Extended defects in graphene, such as linear edges, break the translational
invariance and can also have an impact on the symmetries specific to massless
Dirac-like quasiparticles in this material. The paper examines the consequences
of a broken Dirac fermion parity in the framework of the effective boundary
conditions varying from the Berry-Mondragon mass confinement to a zigzag edge.
The parity breaking reflects the structural sublattice asymmetry of zigzag-type
edges and is closely related to the previously predicted time-reversal
symmetric edge states. We calculate the local and global densities of the edge
states and show that they carry a specific polarization, resembling, to some
extent, that of spin-polarized materials. The lack of the parity leads to a
nonanalytical particle-hole asymmetry in the edge-state properties. We use our
findings to interpret recently observed tunneling spectra in zigzag-terminated
graphene. We also propose a graphene-based tunneling device where the
particle-hole asymmetric edge states result in a strongly nonlinear
conductance-voltage characteristics, which could be used to manipulate the
tunneling transport.Comment: 8 pages, 5 figures, to be published in Phys. Rev.
An Efficient Algorithm for Optimizing Adaptive Quantum Metrology Processes
Quantum-enhanced metrology infers an unknown quantity with accuracy beyond
the standard quantum limit (SQL). Feedback-based metrological techniques are
promising for beating the SQL but devising the feedback procedures is difficult
and inefficient. Here we introduce an efficient self-learning
swarm-intelligence algorithm for devising feedback-based quantum metrological
procedures. Our algorithm can be trained with simulated or real-world trials
and accommodates experimental imperfections, losses, and decoherence
Sounds Like a Fit! Wording in Recruitment Advertisements and Recruiter Gender Affect Womenβs Pursuit of Career Development Programs via Anticipated Belongingness
Following calls for research to increase gender equality, we investigated women's intentions to pursue career opportunities, in the form of career development programs. We built on lack of fit and signaling theory to argue that women's but not men's pursuit of career opportunities would be influenced by recruiter gender and genderβstereotypical wording in recruitment advertisements. We conducted two studies in Germany. In Study 1 (videoβbased experiment with 329 university students), we found that when a male recruiter used stereotypically masculine compared to feminine wording, female students anticipated lower belongingness, expected lower success of an application, and indicated lower application intentions for career opportunities. These differences in female studentsβ evaluations disappeared when the recruiter was female. While Study 2 (experimental vignette study with 545 employees) replicates the negative effects of masculine wording for female employees; the buffering effect of female recruiters was only replicated for younger, but not for older female employees. Women's anticipated belongingness mediated the relationship between advertisement wording and application intentions when the recruiter was male. Recruiter gender and wording had no effects on men. Our work contributes to a better understanding of when and why contextual characteristics in the recruitment process influence women's pursuit of career opportunities
New flexible motion estimation technique for scalable MPEG encoding using display frame order and multi-temporal references
The applicability of MPEG video coding can be improved by scaling both the algorithmic complexity and resource usage appropriately for the intended device and application. For this purpose, we present a new technique for motion estimation, based on a scalable three-stage process including frame processing in display order, approximation of motion vector fields using multiple references and optional quality refinements. Experiments show that the computational effort is scalable with a factor of 14, resulting in a global variation of 7 dB SNR in picture quality. At full processing, our technique slightly outperforms a 32Γ32 full search motion estimation. The technique forms a valuable contribution to mobile MPEG coding applications, following the scalability concepts introduced by Mietens, de With and Hentschel (see IEEE Int. Conf. on Image Proc. (ICIP 2001), vol.3, p.462-465, Oct. 2001)
ΠΠ΅ΡΠΎΠ΄ ΡΡΡΡ ΡΡΠΎΡΠΎΠ½Π½Π΅Π³ΠΎ ΡΠ»ΠΈΡΠ½ΠΈΡ ΠΎΠ½ΡΠΎΠ»ΠΎΠ³ΠΈΠΉ Π½Π° ΡΠ·ΡΠΊΠ΅ OWL 2
ΠΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ Π°Π»Π³ΠΎΡΠΈΡΠΌ ΡΡΡΡ
ΡΡΠΎΡΠΎΠ½Π½Π΅Π³ΠΎ ΡΠ»ΠΈΡΠ½ΠΈΡ ΠΎΠ½ΡΠΎΠ»ΠΎΠ³ΠΈΠΉ ΠΏΡΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°ΡΠ΅Π»ΡΡΠΊΠΎΠΌ ΡΠ΅Π΄Π°ΠΊΡΠΈΡΠΎΠ²Π°Π½ΠΈΠΈ ΠΏΡΡΡΠΌ ΠΏΠΎΠΏΠ°ΡΠ½ΠΎΠ³ΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ ΠΎΠ½ΡΠΎΠ»ΠΎΠ³ΠΈΠΉ, ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΡΠΉ Π½Π° Π²ΡΡΠ²Π»Π΅Π½ΠΈΠΈ ΡΠΎΠ²ΠΏΠ°Π΄Π°ΡΡΠΈΡ
ΠΈ ΠΊΠΎΠ½ΡΠ»ΠΈΠΊΡΡΡΡΠΈΡ
ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½Π°Ρ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΡ Π°Π»Π³ΠΎΡΠΈΡΠΌΠ°
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