Guiding center drift atoms

Abstract

Very weakly bound electron-ion pairs in a strong magnetic field are called guiding center drift atoms, since the electron dynamics can be treated by guiding center drift theory. Over a wide range of weak binding, the coupled electron-ion dynamics for these systems is integrable. This paper discusses the dynamics, including the important cross magnetic field motion of an atom as a whole, in terms of the system constants of the motion. Since the dynamics is quasi-classical, quantum numbers are assigned using the Bohr-Sommerfeld rules. Antimatter versions of these guiding center drift atoms likely have been produced in recent experiments.

A theoretical survey of formation of antihydrogen atoms in a Penning trap

“…This leads to the approximate conservations of the magnetron and axial adiabatic invariants, making the system completely separable and therefore fully integrable. This approximation is called the Guiding Center Drift approximation [18].…”

Polarization and Trapping of Weakly Bound Atoms in Penning Trap Fields

“…[5], the nearly circular drift orbits considered here and shown in Fig. 1 are not the only possible motion for the pair.…”

“…In a very weakly bound configuration, the positronẼ E B B drifts in the field of the antiproton, and the antiprotonẼ E B B drifts in the field of the positron. These states, often referred to as giant dipole states [5,8,9], are not considered here. As mentioned in Ref.…”

“…Although expression (6) was written down as the energy of the two particles, it can be derived as a Hamiltonian for the relative motion [5]. From the Hamiltonian, one finds, not surprisingly, that the relative coordinater r undergoes drift motion in the effective potential H=e [i.e., dr r=dt c=eBr r r H ẑ z].…”

“…The dynamics is quasiclassical because the characteristic binding energy is much smaller than the Rydberg energy (typically 4 orders of magnitude smaller). References [5,6] provide an analysis of the internal dynamics of these novel atoms. Figure 1 shows the motion in the limit that is of interest here.…”