515 research outputs found
Quantum switch for single-photon transport in a coupled superconducting transmission line resonator array
We propose and study an approach to realize quantum switch for single-photon
transport in a coupled superconducting transmission line resonator (TLR) array
with one controllable hopping interaction. We find that the single-photon with
arbitrary wavevector can transport in a controllable way in this system. We
also study how to realize controllable hopping interaction between two TLRs via
a superconducting quantum interference device (SQUID). When the frequency of
the SQUID is largely detuned from those of the two TLRs, the variables of the
SQUID can be adiabatically eliminated and thus a controllable interaction
between two TLRs can be obtained.Comment: 4 pages,3 figure
Anti-parity-time symmetry hidden in a damping linear resonator
Phase transition from the over-damping to under-damping states is a
ubiquitous phenomenon in physical systems. However, what kind of symmetry is
broken associated with this phase transition remains unclear. Here, we discover
that this phase transition is determined by an anti-parity-time
(anti-) symmetry hidden in a single damping linear resonator,
which is significantly different from the conventional
anti--symmetric systems with two or more modes. We show that the
breaking of the anti- symmetry yields the phase transition from
the over-damping to under-damping states, with an exceptional point (EP)
corresponding to the critical-damping state. Moreover, we propose an
optomechanical scheme to show this anti- symmetry breaking by
using the optical spring effect in a quadratic optomechanical system. We also
suggest an optomechanical sensor with the sensitivity enhanced significantly
around the EPs for the anti- symmetry breaking. Our work unveils
the anti- symmetry hidden in damping oscillations and hence opens
up new possibilities for exploiting wide anti- symmetry
applications in single damping linear resonators.Comment: 12 pages, 6 figures, Research Highlight by Prof. Cheng-Wei Qiu:
https://www.sciengine.com/SCPMA/doi/10.1007/s11433-023-2195-
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