6 research outputs found
Pinwheel VBS state and triplet excitations in the two-dimensional deformed kagome lattice
Determining ground states of correlated electron systems is fundamental to
understanding novel phenomena in condensed matter physics. A difficulty,
however, arises in a geometrically frustrated system in which the
incompatibility between the global topology of an underlying lattice and local
spin interactions gives rise to macroscopically degenerate ground states,
potentially prompting the emergence of quantum spin states, such as resonating
valence bond (RVB) and valence bond solid (VBS). Although theoretically
proposed to exist in a kagome lattice -- one of the most highly frustrated
lattices in two dimensions (2D) being comprised of corner-sharing triangles --
such quantum-fluctuation-induced states have not been observed experimentally.
Here we report the first realization of the "pinwheel" VBS ground state in the
S=1/2 deformed kagome lattice antiferromagnet Rb2Cu3SnF12. In this system, a
lattice distortion breaks the translational symmetry of the ideal kagome
lattice and stabilizes the VBS state.Comment: 10 pages, 4 figures and Supplemental Informatio
Evaluating the use of the Child and Adolescent Intellectual Disability Screening Questionnaire (CAIDS-Q) to estimate IQ in children with low intellectual ability
In situations where completing a full intellectual assessment is not possible or desirable the clinician or researcher may require an alternative means of accurately estimating intellectual functioning. There has been limited research in the use of proxy IQ measures in children with an intellectual disability or low IQ. The present study aimed to provide a means of converting total scores from a screening tool (the Child and Adolescent Intellectual Disability Screening Questionnaire: CAIDS-Q) to an estimated IQ. A series of linear regression analyses were conducted on data from 428 children and young people referred to clinical services, where FSIQ was predicted from CAIDS-Q total scores. Analyses were conducted for three age groups between ages 6 and 18 years. The study presents a conversion table for converting CAIDS-Q total scores to estimates of FSIQ, with corresponding 95% prediction intervals to allow the clinician or researcher to estimate FSIQ scores from CAIDS-Q total scores. It is emphasised that, while this conversion may offer a quick means of estimating intellectual functioning in children with a below average IQ, it should be used with caution, especially in children aged between 6 and 8 years old
Bose-Einstein Condensation in Magnetic Insulators
The elementary excitations in antiferromagnets are magnons, quasiparticles
with integer spin and Bose statistics. In an experiment their density is
controlled efficiently by an applied magnetic field and can be made finite to
cause the formation of a Bose-Einstein condensate (BEC). Studies of magnon
condensation in a growing number of magnetic materials provide a unique window
into an exciting world of quantum phase transitions (QPT) and exotic quantum
states.Comment: 17 pages, 3 figure