Metal-to-insulator crossover in alkali doped zeolite.

We report a systematic nuclear magnetic resonance investigation of the (23)Na spin-lattice relaxation rate, 1/T1, in sodium loaded low-silica X (LSX) zeolite, Nan/Na12-LSX, for various loading levels of sodium atoms n across the metal-to-insulator crossover. For high loading levels of n ≥ 14.2, 1/T1T shows nearly temperature-independent behaviour between 10 K and 25 K consistent with the Korringa relaxation mechanism and the metallic ground state.

Absence of Jahn-Teller transition in the hexagonal Ba3CuSb2O9 single crystal.

With decreasing temperature, liquids generally freeze into a solid state, losing entropy in the process. However, exceptions to this trend exist, such as quantum liquids, which may remain unfrozen down to absolute zero owing to strong quantum entanglement effects that stabilize a disordered state with zero entropy. Examples of such liquids include Bose-Einstein condensation of cold atoms, superconductivity, quantum Hall state of electron systems, and quantum spin liquid state in the frustrated magnets.

Tuning of the ground state in electron doped anthracene.

High quality bulk samples of anthracene (AN) doped with potassium (K) in 1 : 1 and 2 : 1 stoichiometries were successfully prepared by a method involving a room temperature solid-state mechanical diffusion process prior to intercalation reactions during heat treatment, and their physical properties were studied using both magnetic and optical measurements. The transfer of almost one electron from K to AN in K1(AN) was confirmed by SQUID and ESR measurements. A pronounced magnetic hump centered at 150 K associated with antiferromagnetic interactions was observed, which can most likely be interpreted in terms of on-site Coulomb repulsions of the Mott insulating states.

Direct observation by neutron diffraction of antiferromagnetic ordering in s electrons confined in regular nanospace of sodalite.

Sodium clusters formed in the regular nanospace of sodalite (aluminosilicate zeolite) are known to show antiferromagnetic order without any magnetic elements. The clusters are arrayed in a body centered cubic structure. We have performed a neutron diffraction study and succeeded in detecting the magnetic Bragg peaks of the s-electron spins for the first time.