Frustrated Heisenberg antiferromagnet on the pyrochlore lattice

Spin-Ice State of the Quantum Heisenberg Antiferromagnet on the Pyrochlore Lattice.

We study the low-temperature physics of the SU(2)-symmetric spin-1/2 Heisenberg antiferromagnet on a pyrochlore lattice and find "fingerprint" evidence for the thermal spin-ice state in this frustrated quantum magnet. Our conclusions are based on the results of bold diagrammatic Monte Carlo simulations, with good convergence of the skeleton series down to the temperature T/J=1/6. The identifica...

Critical slowing down in the geometrically frustrated pyrochlore antiferromagnet Gd2Ti2O7

Longitudinal-field muon spin relaxation experiments have been carried out in the paramagnetic state of singlecrystal Gd2Ti2O7 just above the phase transition at Tm = 1.0 K. At high applied fields the exponential relaxation time T1 is proportional to field, whereas T1 saturates below a crossover field Bc that is ∼2.5 T at 1.5 K and decreases as Tm is approached. At low fields the relaxation rate...

Quantum disorder in the two-dimensional pyrochlore Heisenberg antiferromagnet

We present the results of an exact diagonalization study of the spin-1/2 Heisenberg antiferromagnet on a two-dimensional version of the pyrochlore lattice, also known as the square lattice with crossings or the checkerboard lattice. Examining the low energy spectra for systems of up to 24 spins, we find that all clusters studied have non-degenerate ground states with total spin zero, and big en...

Spin-Ice and Other Frustrated Magnets on the Pyrochlore Lattice

The recent identification of the dysprosium titanate compound Dy2T i2O7 as a “Spin-Ice”, i.e. the spin analog of regular entropic ice of Pauling, has created considerable excitement. The ability to manipulate spins using magnetic fields gives a unique advantage over regular ice in these systems, and has been used to study the recovery of entropy. Predicted magnetization plateaus have been obser...

Heisenberg Antiferromagnet on a Triangular Lattice