The evaluation of the specific heat of an open damped quantum system is a subtle issue. One possible route is based on the thermodynamic partition function which is the ratio of the partition functions of system plus bath and of the bath alone. For the free damped particle it has been shown, however, that the ensuing specific heat may become negative for appropriately chosen environments. Being...

We study the scaling of entanglement in low-energy states of quantum many-body models on lattices of arbitrary dimensions. We allow for unbounded Hamiltonians such that systems with bosonic degrees of freedom are included. We show that if at low enough temperatures the specific heat capacity of the model decays exponentially with inverse temperature, the entanglement in every lowenergy state sa...

No molecular theory of the specific heat of liquids has been deduced till now. The considerations given in this paper may be regarded as a first attempt to solve that problem. Most molecular theories of solutions regard the solvent as a continuum, treating only the solute as composed of molecules. In this theory this simplification is made wherever possible. For the treatment of certain phenome...

We study the thermodynamics of disordered elastic systems, applied to vortex lattices in the Bragg glass phase. Using the replica variational method we compute the specific heat of pinned vortons in the classical limit. We find that the contribution of disorder is positive, linear at low temperature, and exhibits a maximum. It is found to be important compared to other contributions, e.g., core...

We measured the heat capacity on random alloys of Nd1−xCaxB6 (x < 0.4) in the 0.4 to 300 K temperature range. We calculated the lattice contribution to the specific heat, arising from the Debye-type phonons of the boron framework and Einstein-type oscillators of the cation sublattice. Subtracting lattice and Schottky-type contributions from the measured heat capacity, we find that the electroni...