A robust boson dispenser: Quantum state preparation in interacting many-particle systems

We present a technique to control the spatial state of a small cloud of interacting particles at low temperatures with almost perfect fidelity using spatial adiabatic passage. To achieve this, the resonant trap energies of the system are engineered in such a way that a single, well-defined eigenstate connects the initial and desired states and is isolated from the rest of the spectrum. We apply this procedure to the task of separating a well-defined number of particles from an initial cloud and show that it can be implemented in radio-frequency traps using experimentally realistic parameters.Comment: 10 pages, 9 figure

State engineering in one-dimensional quantum gases

The development of quantum technologies requires the understanding, controlling and engineering of quantum states of interacting systems, a challenge currently driven by experimental progress. In this work I study, both analytically and numerically, two specific models of one-dimensional ultracold atomic systems to determine their states and accessible dynamical behaviour. The first part of the work deals with the creation of a bosonic atom dispenser, a tool which would allow to deterministically separate any number of atoms from an interacting ultracold gas or create a many-particle noon state. By engineering an effectively three-level system, I show that a robust adiabatic process exists that connects the initial and target Fock states. Moreover, I demonstrate its potential to be experimentally implemented using radio-frequency traps. In the second part, I derive an analytical single-particle solution for the arbitrary finite Kronig–Penney model. In this model the atoms are trapped in an infinite square well which contains an arbitrary number of arbitrarily positioned point-like barriers of arbitrary heights. I also demonstrate that using certain parameters in the model as extra (virtual) dimensions one can observe the emergence of higher-dimensional physics in this one-dimensional system. In particular, I show the appearance of edge states and the emergence of a Hofstadter butterfly-like momentum spectrum in various configurations of the model. Finally, using the single-particle solutions, I study many-body correlations in a gas of either infinitely repulsive bosons or non-interacting fermions.Okinawa Institute of Science and Technology Graduate Universit

Entanglement in spatial adiabatic processes for interacting atoms

We study the dynamics of the non-classical correlations for few atom systems in the presence of strong interactions for a number of recently developed adiabatic state preparation protocols. We show that entanglement can be created in a controlled fashion and can be attributed to two distinct sources, the atom-atom interaction and the distribution of atoms among different traps.Comment: 9 pages, 3 figure