Low-Temperature Dynamical Structure Factor of the Two-Leg Spin-1/2 Heisenberg Ladder

Understand

We determine the dynamical structure factor of the two-leg spin-1/2 Heisenberg ladder at low temperatures in the regime of strong rung coupling.

• The dominant feature at zero temperature is the coherent triplon mode.
• We show that the lineshape of this mode broadens in a non-symmetric way at finite temperatures and that the degree of asymmetry increases with temperature.
• We also show that at low frequencies a temperature induced resonance akin to the Villain mode in the spin-1/2 Heisenberg Ising chain emerges.