Many-atom–cavity QED system with homogeneous atom–cavity coupling

Quantum Many Body System at Integer Coupling

The 1/r2 quantum many body problem, and the closely related Haldane-Shastry 1/r2 Heisenberg chain, are the subject of intense theoretical study at present, due in part to their relationship to an ideal gas obeying fractional statistics (see [1] for a review). One direction of study has been the exact calculation of some ground state correlation functions [1-5]. Let us briefly summarize the main...

Homogeneous Rigid Body Mechanics with Elastic Coupling

Geometric algebra is used in an essential way to provide a coordinatefree approach to Euclidean geometry and rigid body mechanics that fully integrates rotational and translational dynamics. Euclidean points are given a homogeneous representation that avoids designating one of them as an origin of coordinates and enables direct computation of geometric relations. Finite displacements of rigid b...

Coupling in Systems with Many Processors

Switchable ultrastrong coupling in circuit QED.

We propose different designs of switchable coupling between a superconducting flux qubit and a microwave transmission line. They are based on two or more loops of Josephson junctions which are directly connected to a closed (cavity) or open transmission line. In both cases the circuit induces a coupling that can be modulated in strength, reaching the so-called ultrastrong coupling regime in whi...

Strong Coupling Qed Breaks Chiral Symmetry

We show that the strong coupling limit of d-dimensional quantum electrodynamics with 2/2 flavors of fermions can be mapped onto the s=1/2 quantum Heisenberg antiferromagnet in d-1 space dimensions. The staggered Néel order parameter is the expectation value of a mass operator in QED and the spin-waves are pions. We speculate that the chiral symmetry breaking phase transition corresponds to a tr...