BROWNIAN MOTORS BASED ON ELECTRIC DIPOLE INTERACTION

2003 ◽  
Vol 17 (07) ◽  
pp. 281-289 ◽  
Author(s):  
HONGWEI ZHANG ◽  
LIANHE ZHI ◽  
YUXIAO LI
Keyword(s):  
Electric Dipole ◽  
Dipole Interaction ◽  
Stationary Probability ◽  
Transition Rates ◽  
Directed Motion ◽  
Brownian Motors ◽  
Probability Current ◽  
Electric Dipoles ◽  
Electric Dipole Interaction ◽  
Optimal Values

Brownian motors based on electric dipoles interaction are studied. Directed motion is induced by the transitions of the electric dipoles potentials between two states. The stationary probability current of the Brownian motors is evaluated. The current is sensitive to temperature and the values of the transition rates between two states. There are optimal values of temperature and the transition rates for the current, and for a suitable choice of the transition rates the current can be reversed.

DIRECTED MOTION OF BROWNIAN MOTORS: A RATCHET MODEL OF TWO-COUPLED MOLECULAR MOTORS

2007 ◽  
Vol 21 (28) ◽  
pp. 1915-1921 ◽  
Author(s):  
SHUTANG WEN ◽  
HONGWEI ZHANG ◽  
LEIAN LIU ◽  
XIAOFENG SUN ◽  
YUXIAO LI
Keyword(s):  
Molecular Motors ◽  
Particle System ◽  
Langevin Equations ◽  
Transition Rates ◽  
Neck Length ◽  
Directed Motion ◽  
Mean Velocity ◽  
Positive Direction ◽  
Brownian Motors ◽  
The Individual

We investigated the motion of two-head Brownian motors by introducing a model in which the two heads coupled through an elastic spring is subjected to a stochastic flashing potential. The ratchet potential felt by the individual head is anti-correlated. The mean velocity was calculated based on Langevin equations. It turns out that we can obtain a unidirectional current. The current is sensitive to the transition rates and neck length and other parameters. The coupling of transition rate and neck length leads to variations both in the values and directions of currency. With a larger neck length, the bi-particle system has a larger velocity in one direction, while with a smaller neck length, it has a smaller velocity in the other direction. This is very likely the case of myosins with a larger neck length and larger velocity in the positive direction of filaments and kinesins with a smaller neck length and smaller velocity in the negative direction of microtubules. We also further investigated how current reversal depended on the neck length and the transition rates.

DYNAMICS OF A FERMI SYSTEM IN A BLACKBODY RADIATION FIELD

2002 ◽  
Vol 11 (05) ◽  
pp. 379-386 ◽  
Author(s):  
ELIADE STEFANESCU ◽  
AUREL SANDULESCU
Keyword(s):  
Master Equation ◽  
Shell Model ◽  
Radiation Field ◽  
Electric Dipole ◽  
Fermi System ◽  
Dipole Interaction ◽  
Blackbody Radiation ◽  
Quantum Master Equation ◽  
Matrix Elements ◽  
Electric Dipole Interaction

We derive a quantum master equation for a system of fermions coupled to the blackbody radiation field through the electric-dipole interaction. This equation is of Lindblad's form, with a hamiltonian part of the shell-model, and a dissipative art with microscopic coefficients, depending on physical constants, matrix elements, and parametrically only on temperature.

Comment on "Electric dipole interaction in quantum optics"

1980 ◽  
Vol 22 (6) ◽  
pp. 2894-2895 ◽  
Author(s):  
E. A. Power ◽  
T. Thirunamachandran
Keyword(s):  
Quantum Optics ◽  
Electric Dipole ◽  
Dipole Interaction ◽  
Electric Dipole Interaction
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