Real Time Dynamics of a Spin Chain with Dzyaloshinskii-Moriya Interactions: Spiral Formation and Quantum Spin Oscillations
Published in Physical Review B, 2011
The Dzyaloshinskii-Moriya interaction has a relativistic nature and is responsible for the presence of weak ferromagnetism in a variety of antiferromagnetic compounds. Although its magnitude is expected to be negligible compared to the exchange interaction coupling spins, there are instances where it is strong enough to create remarkable spin-spiral structures.
In this paper I studied the evolution of a spin-$1/2$ Heisenberg chain after a quantum quench: applying a transverse magnetic field aligning all the spins along a horizontal direction and suddenly removing the field. By using DMRG, complemented with analytical solutions to the two-spin oscillatory quantum dynamics and the classical many-body dynamics, I could understand the nature of spiral propagation in the spin chain at short times.