2,260 research outputs found
Decoherence and Spin Echo in Biological Systems
The spin echo approach is extended to include bio-complexes for which the
interaction with dynamical noise is strong. Significant restoration of the free
induction decay signal due to homogeneous (decoherence) and inhomogeneous
(dephasing) broadening is demonstrated analytically and numerically, for both
an individual dimer of interacting chlorophylls and for an ensemble of dimers.
This approach is based on an exact and closed system of ordinary differential
equations that can be easily solved for a wide range of parameters that are
relevant for bio-applications.Comment: 5 pages, 5 figure
Non-Hermitian Adiabatic Quantum Optimization
We propose a novel non-Hermitian adiabatic quantum optimization algorithm.
One of the new ideas is to use a non-Hermitian auxiliary "initial'' Hamiltonian
that provides an effective level repulsion for the main Hamiltonian. This
effect enables us to develop an adiabatic theory which determines ground state
much more efficiently than Hermitian methods.Comment: Minor corrections, 1 figure, 9 page
Non-Hermitian description of a superconducting phase qubit measurement
We present an approach based on a non-Hermitian Hamiltonian to describe the
process of measurement by tunneling of a phase qubit state. We derive simple
analytical expressions which describe the dynamics of measurement, and compare
our results with those experimentally available.Comment: 8 pages, 4 figure
Narrow scope for resolution-limit-free community detection
Detecting communities in large networks has drawn much attention over the
years. While modularity remains one of the more popular methods of community
detection, the so-called resolution limit remains a significant drawback. To
overcome this issue, it was recently suggested that instead of comparing the
network to a random null model, as is done in modularity, it should be compared
to a constant factor. However, it is unclear what is meant exactly by
"resolution-limit-free", that is, not suffering from the resolution limit.
Furthermore, the question remains what other methods could be classified as
resolution-limit-free. In this paper we suggest a rigorous definition and
derive some basic properties of resolution-limit-free methods. More
importantly, we are able to prove exactly which class of community detection
methods are resolution-limit-free. Furthermore, we analyze which methods are
not resolution-limit-free, suggesting there is only a limited scope for
resolution-limit-free community detection methods. Finally, we provide such a
natural formulation, and show it performs superbly
A non-associative quantum mechanics
A non-associative quantum mechanics is proposed in which the product of three
and more operators can be non-associative one. The multiplication rules of the
octonions define the multiplication rules of the corresponding operators with
quantum corrections. The self-consistency of the operator algebra is proved for
the product of three operators. Some properties of the non-associative quantum
mechanics are considered. It is proposed that some generalization of the
non-associative algebra of quantum operators can be helpful for understanding
of the algebra of field operators with a strong interaction.Comment: one typo in Eq. (23) is correcte
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