Gating ratchet for cold atoms.
نویسندگان
چکیده
We demonstrate experimentally a gating ratchet with cold rubidium atoms in a driven near-resonant optical lattice. A single-harmonic periodic modulation of the optical potential depth is applied, together with a single-harmonic rocking force. Directed motion is observed as a result of the breaking of the symmetries of the system.
منابع مشابه
Controlling the ratchet effect for cold atoms.
Low-order quantum resonances manifested by directed currents have been realized with cold atoms. Here we show that by increasing the strength of an experimentally achievable delta-kicking ratchet potential, quantum resonances of a very high order may naturally emerge and can induce larger ratchet currents than low-order resonances, with the underlying classical limit being fully chaotic. The re...
متن کاملChaotic Hamiltonian Ratchets with Cold Atoms
Currently there is a great amount of scientific research directed at ratchet devices and mechanisms. Initially stimulated by a need to understand biological systems, the field has widened to encompass mesoscopic and atomic physics as well as quantum effects. The great majority of this effort has been directed at systems which include noise (Brownian ratchets). Comparatively little work has been...
متن کاملQuantum ratchets in dissipative chaotic systems.
Using the method of quantum trajectories, we study a quantum chaotic dissipative ratchet appearing for particles in a pulsed asymmetric potential in the presence of a dissipative environment. The system is characterized by directed transport emerging from a quantum strange attractor. This model exhibits, in the limit of small effective Planck constant, a transition from quantum to classical beh...
متن کاملMonte Carlo simulations of cold atom ratchets
This thesis reports the theoretical study of several cold atom ratchet systems. In particular the focus of the work is the determ ination of the ratchet current as a function of the ratchet param eters through analysis of the system symmetries and through numerical simulation. Ratchets are devices th a t exhibit directed motion in the absence of net forces. It is necessary to drive them away fr...
متن کامل- m at . o th er ] 8 S ep 2 00 4 Ratchet effect for cold atoms in an optical lattice Emil Lundh and
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 times in the limit where the potential is weak and quantum diffusion dominates, while current reversal is obtained for stronger potentials. A single paramete...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 100 4 شماره
صفحات -
تاریخ انتشار 2008