31,125 research outputs found
Gain without inversion in quantum systems with broken parities
For a quantum system with broken parity symmetry, selection rules can not
hold and cyclic transition structures are generated. With these
loop-transitions we discuss how to achieve inversionless gain of the probe
field by properly setting the control and auxiliary fields. Possible
implementations of our generic proposal with specific physical objects with
broken parities, e.g., superconducting circuits and chiral molecules, are also
discussed.Comment: 12 pages, 4 figure
An Analysis of the Matching Hypothesis in Networks
The matching hypothesis in social psychology claims that people are more
likely to form a committed relationship with someone equally attractive.
Previous works on stochastic models of human mate choice process indicate that
patterns supporting the matching hypothesis could occur even when similarity is
not the primary consideration in seeking partners. Yet, most if not all of
these works concentrate on fully-connected systems. Here we extend the analysis
to networks. Our results indicate that the correlation of the couple's
attractiveness grows monotonically with the increased average degree and
decreased degree diversity of the network. This correlation is lower in sparse
networks than in fully-connected systems, because in the former less attractive
individuals who find partners are likely to be coupled with ones who are more
attractive than them. The chance of failing to be matched decreases
exponentially with both the attractiveness and the degree. The matching
hypothesis may not hold when the degree-attractiveness correlation is present,
which can give rise to negative attractiveness correlation. Finally, we find
that the ratio between the number of matched couples and the size of the
maximum matching varies non-monotonically with the average degree of the
network. Our results reveal the role of network topology in the process of
human mate choice and bring insights into future investigations of different
matching processes in networks
Tunable one-dimensional microwave emissions from cyclic-transition three-level atoms
By strongly driving a cyclic-transition three-level artificial atom,
demonstrated by such as a flux-based superconducting circuit, we show that
coherent microwave signals can be excited along a coupled one-dimensional
transmission line. Typically, the intensity of the generated microwave is
tunable via properly adjusting the Rabi frequencies of the applied
strong-driving fields or introducing a probe field with the same frequency. In
practice, the system proposed here could work as an on-chip quantum device with
controllable atom-photon interaction to implement a total-reflecting mirror or
switch for the propagating probe field.Comment: 4 pages, 5 figure
Multi-neutron transfer coupling in sub-barrier 32S+90,96Zr fusion reactions
The role of neutron transfers is investigated in the fusion process below the
Coulomb barrier by analyzing 32S+90Zr and 32S+96Zr as benchmark reactions. A
full coupled-channel calculation of the fusion excitation functions has been
performed for both systems by using multi-neutron transfer coupling for the
more neutron-rich reaction. The enhancement of fusion cross sections for
32S+96Zr is well reproduced at sub-barrier energies by NTFus code calculations
including the coupling of the neutron-transfer channels following the Zagrebaev
semiclassical model. We found similar effects for 40Ca+90Zr and 40Ca+96Zr
fusion excitation functions.Comment: Minor corrections, 11 pages, 4 figures, Fusion11 Conference, Saint
Malo, France, 2-6 mai 201
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