Condensed-matter physics: A superfluid is born

Adam Sheldrick

This paper develops a Dirac-sector bridge within the Emergent Condensate Superfluid Medium (ECSM) framework. Previous ECSM work proposed that physical law, spacetime geometry, matter, and quantum behaviour emerge as coherent-limit structures of a finite-response medium. In that sequence, stable localised excitations arise as finite-energy minima of an ECSM stability functional, while bipolar internal response structure provides a route to charge-like imbalance, two-state coherent orientation, SU(2) symmetry, Pauli algebra, Born projection weights, exchange antisymmetry, and Bell-type correlations. The present work asks whether this nonrelativistic Pauli/SU(2) quantum chain admits a relativistic completion. In standard physics, the Dirac equation arises when one requires a first-order relativistic quantum equation whose square recovers the relativistic energy-momentum relation. This requirement forces the Clifford algebra of gamma matrices and naturally introduces spinor structure, antiparticle branches, and relativistic fermionic propagation. In ECSM, this paper reinterprets the Dirac/Clifford structure as

Henk T. C. Stoof

Cecil T. Lane, E. Maxwell

Christopher Mudry

The aim of this book is to introduce a graduate student to selected concepts in condensed matter physics for which the language of field theory is ideally suited. The examples considered in this book are those of superfluidity for weakly interacting bosons, collinear magnetism, and superconductivity. Quantum phase transitions are also treated in the context of quantum dissipative junctions and interacting fermions constrained to one-dimensional position space. The style of presentation is sufficiently detailed and comprehensive that it only presumes familiarity with undergraduate physics. Readership: Graduate students and researchers interested in field theory in condensed matter physics.

K.H. Bennemann, John B. Ketterson

N Fabbri, ], David Clément +3 more

In condensed-matter physics, inelastic light-scattering provides a powerful method to investigate the system under study. It allows accessing the correlation functions which could identify dierent many-body states. We will report on the investigation of ultracold atoms in optical potentials, which have proved to be an excellent way of realizing simplied models of condensed-matter physics theory in experimental practice. In particular, we studied the modication of the response of an array of one-dimensional samples of 87Rb in a periodic potential across the superfluid to Mott-insulator transition, extracting information about both the dynamical spectral function and the one-particle spectral function.