Impurity spin texture at a deconfined quantum critical point

Understand

The spin texture surrounding a non-magnetic impurity in a quantum antiferromagnet is a sensitive probe of the novel physics of a class of quantum phase transitions between a Neel ordered phase and a valence bond solid phase in square lattice S=1/2 antiferromagnets.

• Using a newly developed T=0 Quantum Monte Carlo technique, we compute this spin texture at these transitions and find that it does not obey the universal scaling form expected at a scale invariant quantum critical point.
• We also identify the precise logarithmic form of these scaling violations.
• Our results are expected to yield important clues regarding the probable theory of these unconventional transitions.