Physics – Quantum Physics
Scientific paper
2009-05-11
Physics
Quantum Physics
Submitted to Journal of Physics A
Scientific paper
We study a slow classical system [particle] coupled to a fast quantum system with discrete energy spectrum. We adiabatically exclude the quantum system and construct an autonomous dynamics for the classical particle in successive orders of the small ratio $\epsilon$ of the characteristic times. It is known that in the order $\epsilon^0$ the particle gets an additional [Born-Oppenheimer] potential, while in the order $\eps^1$ it feels an effective magnetic field related to the Berry phase. In the order $\epsilon^2$ the motion of the classical particle can be reduced to a free [geodesic] motion on a curved Riemannian manifold, with the metric generated by the excluded quantum system. This motion has a number of unusual features, e.g., it combines subspaces of different (Riemannian and pseudo-Riemannian) signature for the metric tensor. In the order $\epsilon^3$ the motion of the classical particle is still described by a Lagrangian, but the latter linearly depends on the particle's acceleration. This implies the existence of a spin tensor [non-orbital angular momentum] for the particle. This spin tensor is related to the momentum via an analogue of the zitterbewegung effect. The Hamiltonian structure of the system is non-trivial and is defined via non-linear Poisson brackets. The linear dependence of the effective classical Lagrangian on higher-order derivatives is seen as well in the higher orders $\epsilon^n$.
Allahverdyan Armen E.
Mehmani Bahar
No associations
LandOfFree
Post-adiabatic forces and Lagrangians with higher-order derivatives does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Post-adiabatic forces and Lagrangians with higher-order derivatives, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Post-adiabatic forces and Lagrangians with higher-order derivatives will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-701222