Temperature-modulation spectroscopy of non-equilibrium systems

In order to devise experiments which give information on the structure of the free energy landscape (FEL), we present a theoretical framework to handle the temperature-modulation spectroscopy. We first test the superposition rule which serves as a basic principle of the linear response analysis of the temperature modulation. To this end, we exploit a simple two-state system and show that the response to a step modulation can be represented by the difference of two relaxations against two different temperature jumps. We also show that the response can be described by a properly defined effective temperature.