Theory of quantum systems

Abstract:

We numerically investigate momentum diffusion rates for the pulse kicked rotor across the quantum to classical transition as the dynamics are made more macroscopic by increasing the total system action. For initial and late time rates we observe an enhanced diffusion peak which shifts and scales with changing kick strength, and we also observe distinctive peaks around quantum resonances. Our investigations take place in the context of a system of ultracold atoms which is coupled to its environment via spontaneous emission decoherence, and the effects should be realizable in ongoing experiments.

Abstract:

A chemical autonomous agent is defined as a reproducing molecular system that carries out a thermodynamic work cycle, reminiscent of the earliest prebiotic replicators that harnessed free energy. The efficiency with which free energy is utilized to promote replication is a measure of the selective fitness of such a system. Simulations of the operation of a typical autonomous agent over a wide range of possible parameter settings reveals a fitness landscape with a well-defined maximum and a variety of features that are amenable to interpretation in terms of evolutionary concepts.