Matter waves inside periodic potentials are well known from solid-state physics, where
electrons interacting with a crystal lattice are considered. Atomic Bose-Einstein condensates …

Persistent currents in annular geometries have played an important role in disclosing the
quantum phase coherence of superconductors and mesoscopic electronic systems …

Atomtronics, is an emerging interdisciplinary field that seeks to develop new functional
methods by creating devices and circuits where ultracold atoms, often superfluids, have a …

We present the theory of bosonic systems with multiple condensates, providing a unified
description of various model systems that are found in the literature. We discuss how …

Abstract Superflow of a Bose–Einstein condensate in an optical lattice is represented by a
Bloch wave, a plane wave with periodic modulation of the amplitude. We review the …

The scope of analog simulation in atomic, molecular, and optical systems has expanded
greatly over the past decades. Recently, the idea of synthetic dimensions—in which …

Superposition states of circular currents of exciton-polaritons mimic the superconducting flux
qubits. The phase of a polariton fluid must change by an integer number of 2 π when going …

We investigate the band structure of a Bose-Einstein condensate in a one-dimensional
periodic potential by calculating stationary solutions of the Gross-Pitaevskii equation, which …

Geometric frustration of particle motion in a kagome lattice causes the single-particle band
structure to have a flat s-orbital band. We probe this band structure by placing a Bose …

Using a simple model for nonlinear Landau-Zener tunneling between two energy bands of a
Bose-Einstein condensate in a periodic potential, we find that the tunneling rates for the two …