Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond

Abstract

We review recent developments in the physics of ultracold atomic and molecular gases in optical lattices. Such systems are nearly perfect realisations of various kinds of Hubbard models, and as such may very well serve to mimic condensed matter phenomena. We show how these systems may be employed as quantum simulators to answer some challenging open questions of condensed matter, and even high energy physics. After a short presentation of the models and the methods of treatment of such systems, we discuss in detail, which challenges of condensed matter physics can be addressed with (i) disordered ultracold lattice gases, (ii) frustrated ultracold gases, (iii) spinor lattice gases, (iv) lattice gases in "artificial" magnetic fields, and, last but not least, (v) quantum information processing in lattice gases. For completeness, also some recent progress related to the above topics with trapped cold gases will be discussed.

Exploring the quantum speed limit with computer games

“…To better understand this, we have made a low-dimensional rendering of the optimization landscape. These studies show why traditional optimization methods fail near the quantum speed limit [7,8,9], and they bring promise that combined analyses of optimization land- Quantum physics holds the potential of unprecedented technological advances in the realms of computing [10] and simulations [11]. To ensure functionality, all quantum operations must be executed near perfection, requiring highly optimized operations with fidelities above F ≥ 0.999 [12].…”

“…Their regular spacing offers the possibility of creating a scalable quantum computer, which is a challenge for other available architectures [21]. Several proposals for the implementation of quantum computing in this system have been proposed, mainly using long range gates or contact interactions [11]. Here we investigate an architecture [6] where contact interaction is achieved by moving atoms on top of each other using a so-called optical tweezer [22,23], a tightly focused off-resonant laser beam.…”

“…We ask whether citizen science projects can be extended from these puzzle and pattern recognition tasks to dynamic challenges, and whether this approach can be implemented on quantum physics problems. In order to investigate these questions we created Quantum Moves 1 , which presents quantum computing operations as games.The quantum computer architecture we gamify employs neutral atoms trapped in optical lattices [11]. By driving the superfluid-Mott insulator transition, samples of hundreds of atoms have been trapped in optical lattices with an unprecedented purity [19,20].…”

“…Quantum physics holds the potential of unprecedented technological advances in the realms of computing [10] and simulations [11]. To ensure functionality, all quantum operations must be executed near perfection, requiring highly optimized operations with fidelities above F ≥ 0.999 [12].…”

“…The quantum computer architecture we gamify employs neutral atoms trapped in optical lattices [11]. By driving the superfluid-Mott insulator transition, samples of hundreds of atoms have been trapped in optical lattices with an unprecedented purity [19,20].…”