Scaling of the thermal spectral function for quantum critical bosons in one dimension

Understand

We present an improved scheme for the precise evaluation of finite-temperature response functions of strongly correlated systems in the framework of the time-dependent density matrix renormalization group.

• The maximum times that we can reach at finite temperatures T are typically increased by a factor of two, when compared against the earlier approaches.
• This novel scheme, complemented with linear prediction, allows us now to evaluate dynamic correlators for interacting bosons in one dimension.
• We demonstrate that the considered spectral function in the quantum critical regime with dynamic critical exponent z=2 is captured by the universal scaling form S(k,omega)=(1/T)*Phi(k/sqrt(T),omega/T) and calculate the scaling function precisely.