5,613 research outputs found
Quantum Coins, Dice and Children: Probability and Quantum Statistics
We discuss counterintuitive aspects of probabilities for systems of identical
particles obeying quantum statistics. Quantum coins and children (two level
systems) and quantum dice (many level systems) are used as examples. It is
emphasized that, even in the absence of interactions, (anti)symmetrizations of
multi-particle wavefunctions destroy statistical independences and often lead
to dramatic departures from our intuitive expectations.Comment: 8 pages in REVTe
Magnetic excitations and anomalous spin wave broadening in multiferroic FeV2O4
We report on the different roles of two orbital-active Fe at the A
site and V at the B site in the magnetic excitations and on the
anomalous spin wave broadening in FeVO. FeVO exhibits
three structural transitions and successive paramagnetic (PM)-collinear
ferrimagnetic (CFI)-noncollinear ferrimagnetic (NCFI) transitions. The
high-temperature tetragonal/PM -orthorhombic/CFI transition is accompanied by
the appearance of an energy gap with a high magnitude in the magnetic
excitations due to strong spin-orbit coupling induced anisotropy at the
Fe site. While there is no measurable increase in the energy gap from
the orbital ordering of V at the orthorhombic/CFI-tetragonal/NCFI
transition, anomalous spin wave broadening is observed in the orthorhombic/CFI
state due to V spin fluctuations at the B site. The spin wave broadening
is also observed at the zone boundary without softening, which is discussed in
terms of magnon-phonon coupling.Comment: 4 pages, 3 figures, including one supplemental materia
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