Discovery of quantum phases in the Shastry-Sutherland compound SrCu(BO) under extreme conditions of field and pressure.

The 2-dimensional layered oxide material SrCu(BO), long studied as a realization of the Shastry-Sutherland spin topology, exhibits a range of intriguing physics as a function of both hydrostatic pressure and magnetic field, with a still debated intermediate plaquette phase appearing at approximately 20 kbar and a possible deconfined critical point at higher pressure. Here, we employ a tunnel diode oscillator (TDO) technique to probe the behavior in the combined extreme conditions of high pressure, high magnetic field, and low temperature. We reveal an extensive phase space consisting of multiple magnetic analogs of the elusive supersolid phase and a magnetization plateau.

Emergent bound states and impurity pairs in chemically doped Shastry-Sutherland system.

Impurities often play a defining role in the ground states of frustrated quantum magnets. Studies of their effects are crucial in understanding of the phase diagram in these materials. SrCu(BO), an experimental realization of the Shastry-Sutherland (SS) lattice, provides a unique model system for such studies using both experimental and numerical approaches.

Real-space localization and quantification of hole distribution in chain-ladder Sr3Ca11Cu24O41 superconductor.

Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and ladders and to unravel the hole distribution from the atomic scale variations of the O-K near-edge structures. The experimental data unambiguously demonstrate that most of the holes lie within the chain layers.

Supercooled spin liquid state in the frustrated pyrochlore Dy2Ti2O7.

A "supercooled" liquid develops when a fluid does not crystallize upon cooling below its ordering temperature. Instead, the microscopic relaxation times diverge so rapidly that, upon further cooling, equilibration eventually becomes impossible and glass formation occurs. Classic supercooled liquids exhibit specific identifiers including microscopic relaxation times diverging on a Vogel-Tammann-Fulcher (VTF) trajectory, a Havriliak-Negami (HN) form for the dielectric function ε(ω, T), and a general Kohlrausch-Williams-Watts (KWW) form for time-domain relaxation.

Magnetic nanopantograph in the SrCu2(BO3)2 Shastry-Sutherland lattice.

Magnetic materials having competing, i.e., frustrated, interactions can display magnetism prolific in intricate structures, discrete jumps, plateaus, and exotic spin states with increasing applied magnetic fields.

Magnetic phase transitions and magnetic entropy in the antiferromagnetic pyrochlores (Er Y )TiO.

We present the results of experimental determination of the heat capacity of the pyrochlore ErTiO as a function of temperature (0.35-300 K) and magnetic field (up to 9 T), and for magnetically diluted solid solutions of the general formula (Er Y )TiO (≤0.471).