112,077 research outputs found
A solution set for fine games
Bumb and Hoede have shown that a cooperative game can be split into two games, {\it the reward game} and {\it the fine game}, by considering the sign of quantities in the c-diagram of the game. One can then define a solution for the original game as , where is a solution for the reward game and is a solution for the fine game. Due to the distinction of cooperation rewards and fines, for allocating the fines one may use another solution concept than for the rewards
Quantum sensing of rotation velocity based on transverse field Ising model
We study a transverse-field Ising model (TFIM) in a rotational reference
frame. We find that the effective Hamiltonian of the TFIM of this system
depends on the system's rotation velocity. Since the rotation contributes an
additional transverse field, the dynamics of TFIM sensitively responses to the
rotation velocity at the critical point of quantum phase transition. This
observation means that the TFIM can be used for quantum sensing of rotation
velocity that can sensitively detect rotation velocity of the total system at
the critical point. It is found that the resolution of the quantum sensing
scheme we proposed is characterized by the half-width of Loschmidt echo of the
dynamics of TFIM when it couples to a quantum system S. And the resolution of
this quantum sensing scheme is proportional to the coupling strength \delta
between the quantum system S and the TFIM, and to the square root of the number
of spins N belonging the TFIM.Comment: 6 pages,6 figure
Quantum decoherence of excitons in a leaky cavity with quasimode
For the excitons in the quantum well placed within a leaky cavity, the
quantum decoherence of a mesoscopically superposed states is investigated based
on the factorization theory for quantum dissipation. It is found that the
coherence of the exciton superposition states will decrease in an oscillating
form when the cavity field interacting with the exciton is of the form of
quasimode. The effect of the thermal cavity fields on the quantum decoherence
of the superposition states of the exciton is studied and it is observed that
the higher the temperature of the environment is, the shorter the decoherence
characteristic time is.Comment: 1 figure, 7 page
Single-particle machine for quantum thermalization
The long time accumulation of the \textit{random} actions of a single
particle "reservoir" on its coupled system can transfer some temperature
information of its initial state to the coupled system. This dynamic process
can be referred to as a quantum thermalization in the sense that the coupled
system can reach a stable thermal equilibrium with a temperature equal to that
of the reservoir. We illustrate this idea based on the usual micromaser model,
in which a series of initially prepared two-level atoms randomly pass through
an electromagnetic cavity. It is found that, when the randomly injected atoms
are initially prepared in a thermal equilibrium state with a given temperature,
the cavity field will reach a thermal equilibrium state with the same
temperature as that of the injected atoms. As in two limit cases, the cavity
field can be cooled and "coherently heated" as a maser process, respectively,
when the injected atoms are initially prepared in ground and excited states.
Especially, when the atoms in equilibrium are driven to possess some coherence,
the cavity field may reach a higher temperature in comparison with the injected
atoms. We also point out a possible experimental test for our theoretical
prediction based on a superconducting circuit QED system.Comment: 9 pages,4 figures
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