9510454 Uemura Muon spin relaxation (muSR) measurements are proposed to study ground state properties and spin fluctuations in geometrically frustrated spin systems, such as the Kagome lattice and triangular lattice antiferromagnets strontium chromium (x) gallium (12-x) oxygen (19) and lithium nickel oxygen (2), as well as in low-dimensional spin systems, including the doped Haldane spin chain system (yttrium, calcium) (2) barium nickel oxygen (5), the spin-Peierls system (copper, zinc) germanium oxygen (3), the one-dimensional organic conductor aluminum carbon (60), and the spin-ladder cuprates, strontium (n-1) copper (n+1) oxygen (2n). This proposal aims to reveal details of suggested spin-liquid ground states as well as to elucidate the process of destruction of the many-body singlet ground state due to the introduction of imperfections or doped charge carriers. The muSR experiments will be performed at the TRIUMF facility in Vancouver, Canada. %%% Certain configurations of atomic arrangements in solids, such as the triangular or Kagome lattice, tend to prevent the alignment of the magnetic moments of the atoms placed on it, promoting dynamic fluctuations of the moments (spins). Similarly, magnetic ordering is suppressed in low-dimensional arrangements of spins, such as a chain of magnetic moments. In these systems, novel magnetic behavior is expected at low temperatures, including the possibility for the occurrence of a "quantum spin liquid", which is a disordered liquid- like dynamic state of the moments due to quantum-mechanical effects. This proposal aims to reveal the nature of such exotic magnetic behavior by utilizing a novel technique called muon spin relaxation (muSR), which probes the magnetism within solids with radioactive elementary particles, muons, produced at a high-intensity proton accelerator (the TRIUMF facility in Vancouver , Canada).
