Algorithm for Linear Response Functions at Finite Temperatures: Application to ESR Spectrum of s=12 Antiferromagnet Cu Benzoate
Toshiaki Iitaka, Toshikazu Ebisuzaki
We introduce an efficient and numerically stable method for calculating linear response functions chi(q,omega) of quantum systems at finite temperatures. The method is a combination of numerical solution of the time-dependent Schrödinger equation, random vector representation of trace, and Chebyshev polynomial expansion of Boltzmann operator. This method should be very useful for a wide range of strongly correlated quantum systems at finite temperatures. We present an application to the ESR spectrum of s=1 / 2 antiferromagnet Cu benzoate.
arXiv:cond-mat/0212485•Physical Review Letters•Jan 31, 2003•54 citations