Related papers: Computing with Non-equilibrium Ratchets
In this work we propose a ratchet effect which provides a general means of performing clocked logic operations on discrete particles, such as single electrons or vortices. The states are propagated through the device by the use of an…
We explore heat transfer in molecular junctions between two leads in the absence of a finite net thermal bias. The application of an unbiased, time-periodic temperature modulation of the leads entails a dynamical breaking of reflection…
Brownian computers utilize thermal fluctuations as a resource for computation and hold promise for achieving ultra-low-energy computations. However, the lack of a statistical direction in Brownian motion necessitates the incorporation of…
Efficiency of generation of net unidirectional current in an adiabatically driven symmetric periodic potential system is studied. The efficiency shows a maximum, in the case of an inhomogeneous system with spatially varying periodic…
We model an overdamped Brownian particle that is subject to resetting facilitated by a ratchet potential on a spatially periodic domain. This asymmetric potential switches on with a constant rate, but switches off again only upon the…
Ratchets are dynamic systems where particle transport is induced by zero-average forces due to the interplay between nonlinearity and asymmetry. Generally, they rely on the effect of a strong external driving. We show that stationary…
We investigate the transport properties of a new class of ratchets. The device is constructed by applying an ac voltage to the metallic single electron tunneling transistor, and a net transport current is induced by the time-dependent…
We demonstrate that the tunnel oscillations of a biased double quantum dot can be employed as driving source for a quantum ratchet. As a model, we use two capacitively coupled double quantum dots. One double dot is voltage biased and…
Quantum ratchets exhibit asymptotic currents when driven by a time-periodic potential of zero mean if the proper spatio-temporal symmetries are broken. There has been recent debate on whether directed currents may arise for potentials which…
We examine the stochastic energetics of directed quantum transport due to rectification of non-equilibrium thermal fluctuations. We calculate the quantum efficiency of a ratchet device both in presence and absence of an external load to…
We argue that the phase across an asymmetric dc SQUID threaded by a magnetic flux can experience an effective ratchet (periodic and asymmetric) potential. Under an external ac current, a rocking ratchet mechanism operates whereby one sign…
We investigate a one-dimensional electron liquid with two point scatterers of different strength. In the presence of electron interactions, the nonlinear conductance is shown to depend on the current direction. The resulting asymmetry of…
A mechanism for the reduction of dynamic energy dissipation in the computing circuit is described. The resonant circuit with controlled switches conserves the stored energy by recovering upto 90% of energy that would be otherwise lost…
The efficiency of energy transduction in a temporally asymmetric rocked ratchet is studied. Time asymmetry favours current in one direction and suppresses it in the opposite direction due to which large efficiency ~ 50% is readily obtained.…
We study the crossover between classical and quantum dynamics by observing the behavior of a quantum ratchet created by exposing a Bose-Einstein condensate to short pulses of a potential which is periodic in both space and time. Such a…
Directed classical current that increases linearly with time without using a biased external field is obtained in a simple model Hamiltonian system derived from a modified kicked rotor model, by breaking the spatial symmetry of the…
The realization of a directed current for a quantum particle in a flashing asymmetric potential is studied. It is found that a positive current, i.e. in the direction expected for a conventional diffusive ratchet, can be attained at short…
Feedback flashing ratchets are thermal rectifiers that use information on the state of the system to operate the switching on and off of a periodic potential. They can induce directed transport even with symmetric potentials thanks to the…
A possibility to perform single-electron computing without dissipation in the array of tunnel-coupled quantum dots is studied theoretically, taking the spin gate NOT (inverter) as an example. It is shown that the logical operation can be…
Thermal ratchets can extract useful work from random fluctuations. This is common in the molecular scale, such as motor proteins, and has also been used to achieve directional transport in microfluidic devices. In this work, we use the…