19,642 research outputs found
Quantum authentication of classical messages
Although key distribution is arguably the most studied context on which to
apply quantum cryptographic techniques, message authentication, i.e.,
certifying the identity of the message originator and the integrity of the
message sent, can also benefit from the use of quantum resources. Classically,
message authentication can be performed by techniques based on hash functions.
However, the security of the resulting protocols depends on the selection of
appropriate hash functions, and on the use of long authentication keys. In this
paper we propose a quantum authentication procedure that, making use of just
one qubit as the authentication key, allows the authentication of binary
classical messages in a secure manner.Comment: LaTeX, 6 page
Thermodynamics of strongly interacting fermions in two-dimensional optical lattices
We study finite-temperature properties of strongly correlated fermions in
two-dimensional optical lattices by means of numerical linked cluster
expansions, a computational technique that allows one to obtain exact results
in the thermodynamic limit. We focus our analysis on the strongly interacting
regime, where the on-site repulsion is of the order of or greater than the band
width. We compute the equation of state, double occupancy, entropy, uniform
susceptibility, and spin correlations for temperatures that are similar to or
below the ones achieved in current optical lattice experiments. We provide a
quantitative analysis of adiabatic cooling of trapped fermions in two
dimensions, by means of both flattening the trapping potential and increasing
the interaction strength.Comment: 7 pages, 7 figure
Assessing Student Learning in Middle-Division Classical Mechanics/Math Methods
Reliable and validated assessments of introductory physics have been
instrumental in driving curricular and pedagogical reforms that lead to
improved student learning. As part of an effort to systematically improve our
sophomore-level Classical Mechanics and Math Methods course (CM 1) at CU
Boulder, we are developing a tool to assess student learning of CM 1 concepts
in the upper-division. The Colorado Classical Mechanics/Math Methods Instrument
(CCMI) builds on faculty-consensus learning goals and systematic observations
of student difficulties. The result is a 9-question open-ended post-test that
probes student learning in the first half of a two-semester classical mechanics
/ math methods sequence. In this paper, we describe the design and development
of this instrument, its validation, and measurements made in classes at CU
Boulder.Comment: 4 pages, 3 figures, 1 table; submitted to 2013 Proceedings of the
Physics Education Research Conferenc
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