Novel Ordered States in Matters as Microkelvin Temperatures

The objective of this joint project was to observe and elucidate the ground states and related new phenomena which occur near the lowest temperature of the present technology，primarily in the microkelvin region。The scientific output of the project was significant both in quantity and quality，with important contributions to many sub-disciplines of condensed matter physics.These include solid and liquid I D13 II D1He，solid hydrogen，nuclear and electronic magnetic ordering，interactions of spins in low dimensions，and transport properties of electrons.Many of the research results represent breakthroughs in the sub-disciplines.The nuclear ordering temperature in solid I D13西耶D1He was studied in the entire molar-volume range of the bcc phase.Evidence for quantum tunneling of the dislocations in bcc solid I D13锡D1He was observed using the torsion oscillator technique.The change in nuclear magnetism from an antiferromagnetic to a ferromagnetic behavior in submonolayer is similar to th…More at of the second layer and can be explained in terms of a multiple spin exchange model.The pressure-independent contribution to the specific heat per surface area in liquid and solid I D13个D 1 He can be attributed to an amorphous surface solid.The magnetic susceptibility of I D13个D 1 He nano-clusters embedded in matrix of I D 14个D 1 He was also studied.No indication of magnetic order was found in the investigated temperature range.NMR studies in solid hydrogen were used to determine the phase diagram of molecular hydrogen physisorbed on hexagonal boron nitride involving different types of orientational order in 2D.Spontaneous magnetization was observed at the ferromagnetic Weiss temperature=2.6mK in PrPt I D25 I D 2.In a heavy fermion compound CeCu I D 26个D 2，the magnetic susceptibility and thermal expansion coefficient were measured and an indication of magnetic ordering was found at 2 mK.Magnetic studies of even-chain spin effects in the Haldane-gap material NINAZ confirmed that the end-chain spins are S=1/2.The Fractional Quantum Hall State of an even denominator was observed at the n=5/2Landau level filling factor。Less：Less

The objective of this joint project was to observe and elucidate the ground states and related new phenomena which occur near the lowest temperature of the present technology, primarily in the microkelvin region. The scientific output of the project was significant both in quantity and quality, with important contributions to many sub-disciplines of condensed matter physics. These include solid and liquid ィイD13ィエD1He, solid hydrogen, nuclear and electronic magnetic ordering, interactions of spins in low dimensions, and transport properties of electrons. Many of the research results represent breakthroughs in the sub-disciplines.The nuclear ordering temperature in solid ィイD13ィエD1He was studied in the entire molar-volume range of the bcc phase. Evidence for quantum tunneling of the dislocations in bcc solid ィイD13ィエD1He was observed using the torsion oscillator technique. The change in nuclear magnetism from an antiferromagnetic to a ferromagnetic behavior in submonolayer is similar to th … More at of the second layer and can be explained in terms of a multiple spin exchange model. The pressure-independent contribution to the specific heat per surface area in liquid and solid ィイD13ィエD1He can be attributed to an amorphous surface solid. The magnetic susceptibility of ィイD13ィエD1He nano-clusters embedded in matrix of ィイD14ィエD1He was also studied. No indication of magnetic order was found in the investigated temperature range. NMR studies in solid hydrogen were used to determine the phase diagram of molecular hydrogen physisorbed on hexagonal boron nitride involving different types of orientational order in 2D. Spontaneous magnetization was observed at the ferromagnetic Weiss temperature = 2.6mK in PrPtィイD25ィエD2. In a heavy fermion compound CeCuィイD26ィエD2, the magnetic susceptibility and thermal expansion coefficient were measured and an indication of magnetic ordering was found at 2mK. Magnetic studies of even-chain spin effects in the Haldane-gap material NINAZ confirmed that the end-chain spins are S=1/2. The Fractional Quantum Hall State of an even denominator was observed at the n = 5/2 Landau level filling factor. Less