Demonstrating the topological protection of Andreev states in Josephson junctions is an experimental challenge. In particular the telltale 4π periodicity expected for the current phase relation has remained elusive, because of fast parity breaking processes. It was predicted that low temperature ac susceptibility measurements could reveal the topological protection of quantum spin Hall edge states by probing their low energy Andreev spectrum at finite frequency.
View Article and Find Full Text PDFThe protection against backscattering provided by topology is a striking property. In two-dimensional insulators, a consequence of this topological protection is the ballistic nature of the one-dimensional helical edge states. One demonstration of ballisticity is the quantized Hall conductance.
View Article and Find Full Text PDFPolarized neutron scattering measurements on a single crystal of composition CeIn1Sn2 show a broad, single-ion, spectral response centered on a characteristic energy of approximately 9+/-1 meV at the zone boundary point (0 0 1.5). The zone center spectral response is closely similar in form but has a slightly reduced amplitude, smaller by some 20%.
View Article and Find Full Text PDFPhys Rev Lett
December 2005
A favored interpretation of the gamma <--> alpha phase transition in cerium postulates the transformation of the localized 4f state in gamma-Ce to a weakly correlated itinerant 4f band in alpha-Ce. However, results of high-energy neutron inelastic scattering measurements, presented here, show clearly that the magnetic susceptibility response from alpha-Ce follows the Ce3+ form factor despite the large, 30-fold, increase in its spectral width relative to that in gamma-Ce. This observation provides, for the first time, indisputable evidence for the localized character of the 4f state in the alpha phase.
View Article and Find Full Text PDFWe present inelastic neutron scattering experiments, performed near the antiferromagnetic quantum critical point in Ce(Ru0.24Fe0.76)2Ge2.
View Article and Find Full Text PDFBy combining the results of muon spin relaxation and inelastic neutron scattering in the heavy fermion compounds Ce1-xLaxAl3 (0.0
Phys Rev Lett
November 2001
We have used inelastic neutron scattering to determine the magnetic susceptibility chi(q,omega,T) of the non-Fermi-liquid compounds UCu(5-x)Pdx (x = 1,1.5) for energies omega between 0.2 and 2 meV, and for temperatures T between 1.
View Article and Find Full Text PDFWe have performed an inelastic neutron scattering study of the low energy spin dynamics of the heavy fermion compound Ce0.8La0.2Al3 as a function of temperature and external pressure up to 5 kbar.
View Article and Find Full Text PDFPhys Rev B Condens Matter
October 1994
Phys Rev B Condens Matter
October 1993
Phys Rev B Condens Matter
February 1990
Phys Rev B Condens Matter
April 1989
Phys Rev B Condens Matter
October 1987
Phys Rev B Condens Matter
May 1987
Phys Rev B Condens Matter
June 1986