Spin ice is a prototypical state of frustrated magnets, in which Ising spins form a short-range "2-in, 2-out" correlation instead of a long range order due to geometrical frustrations of pyrochlore lattice. Local Ising anisotropy induced by the competition between crystal electric field effect and magnetic interactions play important roles to stabilize such spin-ice correlations. Generally, frustrated magnets show characteristic magnetostrictive responses and in this study, we measured both magnetization and magnetostriction of classical spin ice Ho2Ti2O7 and quantum spin ice Pr2Zr2O7 under high magnetic fields to explore the regime beyond the Ising limit. In the talk, I will give an extensive introduction on basics of spin ice, and present the latest experimental results and the corresponding simulations by McPhase.
Quantum magnets are known to exhibit peculiar properties at the quantum level due to the interaction between the spins of individual atoms or molecules. These materials have a special ordering of the magnetic moments that arise due to the interplay of various quantum effects such as quantum fluctuations, frustration, and entanglement. However, to realize these quantum behaviours one needs access to high-quality materials. In this seminar, we will discuss the challenges of growing high-quality single crystals of different quantum magnets. Two methods we will focus on are the floating-zone growth (travelling-solvent-floating-zone) method and the Czochralski (top-seeded-solution-growth) method to obtain single crystals of materials such as spin-chains, spin-liquids, and high-Tc superconductors. We will see how high-quality single crystals of these quantum magnets allow us to explore their emerging physics at low temperatures including gapless magnetic excitations and novel magnetic ground states.
