Naslov
Synthetic magnetism in quantum gases and photonic lattices

Autori
Dubček, Tena

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Prirodoslovno-matematički fakultet

Mjesto
Zagreb

Datum
22.12

Godina
2017

Stranica
113

Mentor
Buljan, Hrvoje ; Soljačić, Marin

Ključne riječi
synthetic magnetism, ultracold atoms, quantum gases, photonics, photonic lattices, topological matter, Weyl points, protected surface states, fractional statistics, anyons, laser assisted tunneling, grating assisted tunneling, conical diffraction, Tonks-Girardeau gas, pointlike interactions, evolution, synthetic Lorentz force, radiation pressure

Sažetak
Many intriguing phenomena in modern physics are rooted in the coupling of electric charge to magnetic fields. However, it mostly includes quantum many-body systems, which makes these systems hard to address both experimentally—because of the rather extreme conditions they usually require, and theoretically— because of the exponential dependence of the required classical computer memory on the number of quantum system constituents. The solution is found by following Feynman’s idea of the so-called quantum simulators. Namely, as new methods for synthetic magnetism are developed, controllable systems of neutral atoms and photons are governed to realize and simulate various fascinating phenomena, which are typically emergent only in elusive states of matter. The contribution of the work presented in this thesis is twofold. The first part focuses on the role of synthetic magnetism in the research of topological phases. The latter are nowadays causing a lot of excitement, due to their fascinating emergent behavior, which opens the way for diverse technological applications. By taking advantage of tunable synthetic magnetic fields, we point out how topological phases that otherwise rely on complicated space groups and are thus hardly obtainable, can be realized in simple lattice geometries. Namely, we show that Weyl points, and all of the related phenomena, can be experimentally addressed in an experimentally viable ultracold atomic lattice with laser assisted tunneling. We also consider the realization and detection of a state with fractional statistic in an ultracold atomic gas. We demonstrate how standard methods and understanding have to be taken with caution when studying topological matter via quantum simulation and synthetic magnetism. Specifically, we point out that the momentum distribution, one of the key signatures of quantum states of matter, is not a proper observable for a system of anyons. As a substitute, we propose to use the asymptotic single-particle density after expansion of anyons in free space from the state. The second part of the thesis discusses our proposals of new methods for introducing synthetic magnetism in atomic and photonic systems. We show that drawing analogies between different physical systems can yield new ideas in synthetic magnetism, which enables addressing intriguing topological phases and beyond. Namely, we propose a grating assisted tunneling scheme that introduces tunable synthetic magnetic fields in an photonic lattice, inspired by the laser assisted tunneling method for optical lattices. We also introduce an approach for the mapping of light propagation in dielectric structures and ultracold atomic dynamics to intriguing discrete models. By taking advantage of it, we also confirm the applicability of laser assisted tunneling for a Tonks-Girardeau gas in a 1D optical lattice. Finally, we extend the concept of simulation to complex classical, rather than quantum, systems in the presence of magnetism. We propose a method for creating a synthetic Lorentz force in a classical ultracold atomic gas, which was recently experimentally realized through a collaboration with an experimental group.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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