8 research outputs found
Phase diagram of the Shastry-Sutherland Compound SrCu2(BO3)2 under extreme combined conditions of field and pressure
Motivated by the intriguing properties of the Shastry-Sutherland compound
SrCu2(BO3)2 under pressure, with a still debated intermediate plaquette phase
appearing at around 20 kbar and a possible deconfined critical point at higher
pressure upon entering the antiferromagnetic phase, we have investigated its
high-field properties in this pressure range using tunnel diode oscillator
(TDO) measurements. The two main new phases revealed by these measurements are
fully consistent with those identified by infinite Projected Entangled Pair
states (iPEPS) calculations of the Shastry-Sutherland model, a 1/5 plateau and
a 10 x 2 supersolid. Remarkably, these phases are descendants of the
full-plaquette phase, the prominent candidate for the intermediate phase of
SrCu2(BO3)2. The emerging picture for SrCu2(BO3)2 is shown to be that of a
system dominated by a tendency to an orthorhombic distortion at intermediate
pressure, an important constraint on any realistic description of the
transition into the antiferromagnetic phase
Incommensurate two-dimensional checkerboard charge density wave in the low dimensional superconductor Ta4Pd3Te16
We report the observation of a two-dimensional (2D) checkerboard charge
density wave (CDW) in the low-dimensional superconductor Ta4Pd3Te16. By
determining its CDW properties across the temperature-pressure (T-P) phase
diagram and comparing with prototypical CDW materials, we conclude that
Ta4Pd3Te16 features: a) an incommensurate CDW with a mixed character of
dimensions (Q1D considering its needle-like shape along the b-axis, Q2D as the
CDW has checkerboard wavevectors, and 3D because of CDW projections along all
three axes); and b) one of the weakest CDWs compared to its superconductivity
(SC), i.e. enhanced SC with respect to CDW, suggesting an interesting interplay
of the two orders.Comment: Z.S. and S.J.K. contributed equally to this work / Accepted for
publication in Physical Review Research Rapid Communication
Towards understanding the magnetic properties of the breathing pyrochlore compound Ba3Yb2Zn5O11: A single crystal study
Ba3Yb2Zn5O11 is unique among breathing pyrochlore compounds for being in the
nearly decoupled limit where inter-tetrahedron interactions are weak, hosting
isolated clusters or "molecular magnet" like tetrahedra of magnetic ytterbium
(Yb3+) ions. In this work, we present the first study carried out on
single-crystal samples of the breathing pyrochlore Ba3Yb2Zn5O11, using a
variety of magnetometry and neutron scattering techniques along with
theoretical modeling. We employ inelastic neutron scattering to investigate the
magnetic dynamics as a function of applied field (with respect to both
magnitude and direction) down to a temperature of 70 mK, where inelastic
scattering reveals dispersionless bands of excitations as found in earlier
powder sample studies, in good agreement with a single-tetrahedron model.
However, diffuse neutron scattering at zero field and dc-susceptibility at
finite field exhibit features suggesting the presence of excitations at
low-energy that are not captured by the single tetrahedron model. Analysis of
the local structure down to 2 K via pair distribution function analysis finds
no evidence of structural disorder. We conclude that effects beyond the single
tetrahedron model are important in describing the low-energy, low temperature
physics of Ba3Yb2Zn5O11, but their nature remains undetermined
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Phase Diagram of YbZnGaO4 in Applied Magnetic Field
Recently, Yb-based triangular lattice antiferromagnets have garnered
significant interest as possible quantum spin liquid candidates. One example is
YbMgGaO4, which showed many promising spin liquid features, but also possesses
a high degree of disorder owing to site-mixing between the non-magnetic
cations. To further elucidate the role of chemical disorder and to explore the
phase diagram of these materials in applied field, we present neutron
scattering and sensitive magnetometry measurements of the closely related
compound, YbZnGaO4. Our results suggest a difference in magnetic anisotropy
between the two compounds, and we use key observations of the magnetic phase
crossover to motivate an exploration of the field- and exchange
parameter-dependent phase diagram, providing an expanded view of the available
magnetic states in applied field. This enriched map of the phase space serves
as a basis to restrict the values of parameters describing the magnetic
Hamiltonian with broad application to recently discovered related materials
Recommended from our members
Phase Diagram of YbZnGaO4 in Applied Magnetic Field
Recently, Yb-based triangular lattice antiferromagnets have garnered
significant interest as possible quantum spin liquid candidates. One example is
YbMgGaO4, which showed many promising spin liquid features, but also possesses
a high degree of disorder owing to site-mixing between the non-magnetic
cations. To further elucidate the role of chemical disorder and to explore the
phase diagram of these materials in applied field, we present neutron
scattering and sensitive magnetometry measurements of the closely related
compound, YbZnGaO4. Our results suggest a difference in magnetic anisotropy
between the two compounds, and we use key observations of the magnetic phase
crossover to motivate an exploration of the field- and exchange
parameter-dependent phase diagram, providing an expanded view of the available
magnetic states in applied field. This enriched map of the phase space serves
as a basis to restrict the values of parameters describing the magnetic
Hamiltonian with broad application to recently discovered related materials
Beyond single tetrahedron physics of the breathing pyrochlore compound Ba3Yb2Zn5O11
Recently a new class of quantum magnets, the so-called breathing pyrochlore
spin systems, have attracted much attention due to their potential to host
exotic emergent phenomena. Here, we present magnetometry, heat capacity,
thermal conductivity, Muon-spin relaxation, and polarized inelastic neutron
scattering measurements performed on high-quality single-crystal samples of
breathing pyrochlore compound Ba3Yb2Zn5O11. We interpret these results using a
simplified toy model and provide a new insight into the low-energy physics of
this system beyond the single-tetrahedron physics proposed previously.Comment: includes Supplementary Material