Bonn 2000 – scientific programme

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A: Atomphysik

A 15: Poster I

A 15.21: Poster

Wednesday, April 5, 2000, 10:30–13:00, Aula

Dynamics of angular momentum coupling in an arbitrarily directed magnetic field — •M. Brieger — DLR, Institut für Technische Physik, Pfaffenwaldring 30-40, D-70569 Stuttgart

The choice of an axis of quantization automatically selects those species from a bulk which could become stationary in a field-free environment with related spatial orientations of their coupling angular momenta. But if this axis fails to coincide with the direction of a uniform external magnetic field, a field-imposed tranverse torque forces these atoms’ total angular momenta into steady nutation that cannot be abolished by coupling-related internal torques. Making any stationary state impossible for these atoms, it also causes their energy expectation value to oscillate. This is the result of a rigorous solution to the time-dependent Schrödinger equation describing the coupling dynamics of two spins 1/2 in an external field. Demanding to solve a four-dimensional system of coupled linear differential equations of first order, the bulkiness of even this simplest case already brings the calculations to the verge of becoming infeasible analytically.