We present simulations of some of the early time properties of ultracold neutral plasmas. We focus on three aspects of this system. First, we study the earliest electron dynamics when the initial temperature of the electrons would place them in the strongly coupled regime. We focus on times out to ∼10 plasma periods of the electron but also present results out to ∼85 plasma periods. In particular, we study how the formation of Rydberg atoms leads to heating and how the mass of the ion could enter the dynamics. Second, we study how the ions behave when the electrons are at high temperatures by comparing simulations that treat the electrons as a fluid and simulations that simultaneously include the electrons and ions. For light ions, the electron-ion scattering transfers substantial energy from the electrons to the ions. Finally, we study the ion motion at early times and at low temperatures where the electron evolution and ion motion could be at comparable time scales. This allows a test of electron-ion scattering when the electron plasma is nearly strongly coupled and we find that the recent values for the electron-ion scattering rate underestimate the ion heating in our calculations.

We report on two types of quantum calculations pertaining to a ring of ultracold and identical bosonic ions in a static, external magnetic field. The purpose of these calculation is to give examples of what could be expected in certain types of measurements of the rotation of this ring. The first type of calculation explores how well the ring reaches the rotational ground state when it starts in the ground state of a trapping potential that is then adiabatically switched off; the trapping potential is designed to frustrate the rotation and raise the energy scale to the point where standard cooling techniques could reach the ground state. The second type of calculation shows what kind of rotation signal might be measured using two types of measuring schemes. The focus is on how the signal changes with the temperature of the ring and with how the measurement is performed.

We have performed classical and quantum calculations for a hydrogen atom in a strong magnetic field exposed to a parallel electric field that linearly increases with time. The calculations were performed for the situation where the electron is launched from near the nucleus and for a microcanonical ensemble. For the case of low angular momentum, the classical and quantum calculations are compared. We show that there exist stable classical trajectories at positive energy and that these contribute to the possibility of the atom surviving to strong electric fields. The dependence of the survival probability versus electric field strength can be used to estimate the behaviour of Rydberg anti-hydrogen atoms in the ALPHA and ATRAP experiments.

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