arXiv subjects

M. Sato

Publications and source records attributed to M. Sato.

94 records · Page 6Linked to original sources

arXiv1999

Effect of Pressure on Tiny Antiferromagnetic Moment in the Heavy-Electron Compound URu_2Si_2

We have performed elastic neutron-scattering experiments on the heavy-electron compound URu_2Si_2 for pressure P up to 2.8 GPa. We have found that the antiferrmagnetic (100) Bragg reflection below T_m ~ 17.5 K is strongly enhanced by applying pressure. For P < 1.1 GPa, the staggered moment mu_o at 1.4 K increases linearly from ~ 0.017(3) mu_B to ~ 0.25(2) mu_B, while T_m increases slightly at a rate ~ 1 K/GPa, roughly following the transition temperature T_o determined from macroscopic anomalies. We have also observed a sharp phase transition at P_c ~ 1.5 GPa, above which a 3D-Ising type of antiferromagnetic phase (mu_o ~ 0.4 mu_B) appears with a slightly reduced lattice constant.

cond-mat.str-el↗

arXiv1997

Observation of Spin Freezing in CaV4O9 and CaV2O5 by uSR

We have performed muon spin relaxation and susceptibility measurements of CaV_4O_9 and CaV_2O_5, systems in which spin gap-like behavior has been found. We observe spin freezing in the two compounds below 12K and 50K, respectively. Our results indicate the possibility that a substantial fraction of the of the vanadium magnetic moment is not in a spin singlet sate at low temperatures in either material.

cond-mat.str-el↗

arXiv1995

BRST Symmetric Gaugeon Formalism for Yang-Mills Fields

Yokoyama's gaugeon formalism is knwon to admit $q$-number gauge transformation. We introduce BRST symmetries into the formalism for the Yang-Mills gauge field. Owing to the BRST symmetry, Yokoyama's physical subsidiary conditions are replaced by a single condition of the Kugo-Ojima type. Our physical subsidiary condition is invariant under the $q$-number gauge transformation. Thus, our physical subspace is gauge invariant.

hep-th↗

arXiv1993

Gaugeon Formalism with BRST Symmetry

We provide a BRST symmetric version of Yokoyama's Type I gaugeon formalism for quantum electrodynamics; the similar theory by Izawa can be considered as a BRST symmetrized Type II theory. With the help of the BRST symmetry, Yokoyama's physical subsidiary conditions are replaced by the Kugo-Ojima type condition. As a result, the formalism becomes applicable even in the background gravitational field. We show how the Hilbert spaces of standard formalism in various gauges are embedded in the single Hilbert space of the present formalism. We also give a path integral derivation of the Lagrangian.

hep-th↗