Optimal matrix product states for the Heisenberg spin chain

Critical exponents of the Heisenberg spin chain.

Droplet States in the XXZ Heisenberg Chain

We consider the ground states of the ferromagnetic XXZ chain with spin up boundary conditions in sectors with a fixed number of down spins. This forces the existence of a droplet of down spins in the system. We find the exact energy and the states that describe these droplets in the limit of an infinite number of down spins. We also prove that the droplet states, which were known to be separate...

Quantum Integrals of Motion for the Heisenberg Spin Chain

An explicit expression for all the quantum integrals of motion for the isotropic Heisenberg s = 1/2 spin chain is presented. The conserved quantities are expressed in terms of a sum over simple polynomials in spin variables. This construction is direct and independent of the transfer matrix formalism. Continuum limits of these integrals in both ferrromagnetic and antiferromagnetic sectors are b...

NMR relaxation rates for the spin-1/2 Heisenberg chain.

The spin-lattice relaxation rate 1/T1 and the spin echo decay rate 1/T2G for the spin2 antiferromagnetic Heisenberg chain are calculated using quantum Monte Carlo and maximum entropy analytic continuation. The results are compared with recent analytical calculations by Sachdev. If the nuclear hyperfine form factor Aq is strongly peaked around q = π the predicted lowtemperature behavior [1/T1 ∼ ...

Quantum Phase Transitions and Matrix Product States in Spin Ladders

X iv :q ua nt -p h/ 06 12 20 7v 1 2 5 D ec 2 00 6 Quantum Phase Transitions and Matrix Product States in Spin Ladders M. Asoudeh,∗ V. Karimipour†,‡ and A. Sadrolashrafi§ Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran, Iran (Dated: December 28, 2006) Abstract We investigate quantum phase transitions in ladders of spin 1/2 particles by engineering suitable mat...