4,674 research outputs found
Consumer myopia, compatibility and aftermarket monopolization
In this paper, I show that the standard Bertrand competition argument does not apply when firms compete for myopic consumers who optimize period-by-period. I develop the model in the context of aftermarket. With overlapping-generations of consumers, simultaneous product offerings in the primary market and aftermarket establishes a price floor for the primary good. This constraint prevents aftermarket rents from being dissipated by the primary market competition. Duopoly firms earn positive profits despite price competition with undifferentiated products. Nonetheless, government interventions to reinforce aftermarket competition such as a standardization requirement may lead to the partial collapse of the primary market.aftermarket, Bertrand competition, bounded rationality, standardization.
Energy Spectrum and Phase Transition of Superfluid Fermi Gas of Atoms on Noncommutative Space
Based on the Bogoliubov non-ideal gas model, we discuss the energy spectrum
and phase transition of the superfluid Fermi gas of atoms with a weak
attractive interaction on the canonical noncommutative space. Because the
interaction of a BCS-type superfluid Fermi gas originates from a pair of
Fermionic quasi-particles with opposite momenta and spins, the Hamiltonian of
the Fermi gas on the noncommutative space can be described in terms of the
ordinary creation and annihilation operators related to the commutative space,
while the noncommutative effect appears only in the coefficients of the
interacting Hamiltonian. As a result, we can rigorously solve the energy
spectrum of the Fermi gas on the noncommutative space exactly following the way
adopted on the commutative space without the use of perturbation theory. In
particular, different from the previous results on the noncommutative
degenerate electron gas and superconductor where only the first order
corrections of the ground state energy level and energy gap were derived, we
obtain the nonperturbative energy spectrum for the noncommutative superfluid
Fermi gas, and find that each energy level contains a corrected factor of
cosine function of noncommutative parameters. In addition, our result shows
that the energy gap becomes narrow and the critical temperature of phase
transition from a superfluid state to an ordinary fluid state decreases when
compared with that in the commutative case
Investigating the quantum discord dynamics with a bipartite split of the multiqubit system in the correlated photon-matter model
In this paper, we try to study the quantum discord dynamics in a complex
correlated photon-matter model, which is modified from the
Tavis-Cummings-Hubbard model - a common cavity quantum electrodynamics model.
The target model consists of two hydrogen atoms. A neutral hydrogen molecule
can be obtained through an association reaction and disintegrated through
dissociation reaction. The formation and breaking of covalent bond is
accompanied by the creation and annihilation of phonon. Compared with previous
efforts, studying the quantum discord dynamics of this complicated system is
more challenging than it was for the simple quantum system, which consisted of
a single two-level atom. For convenience, we adopt a bipartite split of the
multiqubit system and the two-qubit von Neumann projective measurement on the
observed subsystem. We attempt to examine the dissipative dynamics in open
quantum system in addition to the unitary evolution of closed quantum system.
We are dedicated to identifying the regularity of quantum correlation as the
basis for future research on more complex quantum systems, specifically
including the impacts of nuclei tunneling effect, covalent bond intensity, and
dissipation strengths of photon and phonon on quantum discord.Comment: 20 pages, 15 figures, 2 table
Studying quantum entanglement and quantum discord in the cavity QED models
Based on the two-qubit Jaynes-Cummings model - a common cavity quantum
electrodynamics model, and extending to modification of the three-qubit
Tavis-Cummings model, we investigate the quantum correlation between light and
matter in bipartite quantum systems. By resolving the quantum master equation,
we are able to derive the dissipative dynamics in open systems. To gauge the
degree of quantum entanglement in the two-qubit system, von Neumann entropy and
concurrence are introduced. Quantum discord, which can properly measure the
quantum correlation in both closed and open systems, is also introduced. In
addition, consideration is given to the impacts of initial entanglement and
dissipation strength on quantum discord. Finally we discussed two different
cases of nuclei motion: quantum and classical.Comment: 12 pages, 9 figure
Modeling and simulating formation of neutral hydrogen molecule in Tavis-Cummings-Hubbard model
A finite-dimensional model of chemistry with two two-level artificial atoms
on quantum dots placed in optical cavities, called the association-dissociation
model of neutral hydrogen molecule, is described. The initial conditions for
formation of the artificial analogue of the neutral hydrogen molecule are
discussed. The motion of the nuclei can be represented in quantum form. The
association of atoms in the molecule is simulated through a quantum master
equation, containing hybridization of atomic orbitals into molecular -
depending on the position of the nuclei. Electron spin transitions of electrons
and spin-spin interactions between electrons and nuclei are also considered.
The influence of temperature variation of photonic modes to unitary evolution
and formation of neutral hydrogen molecule is investigated.Comment: 15 pages, 10 figure
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