activity
20002005
collaborators

5 papers

quant-ph2005

Once more on the equivalence between quantum phase transition phenomena in radiation-matter and magnetic systems

J. G. Brankov, N. S. Tonchev, V. A. Zagrebnov

In answer to the replies of Reslen {\it et al} [arXiv: quant-ph/0507164 (2005)], and Liberti and Zaffino [arXiv:cond-mat/0507019, (2005)], we comment once more on the temperature-d…

quant-ph2005

Comment on equivalence between quantum phase transition phenomena in radiation-matter and magnetic systems

J. G. Brankov, N. S. Tonchev, V. A. Zagrebnov

In this Comment we show that the temperature-dependent effective Hamiltonian derived by Reslen {\it et al} [Europhys. Lett., {\bf 69} (2005) 8] or that one by Liberti and Zaffino […

cond-mat.stat-mech2004

Finite-Size Scaling and Long-Range Interactions

N. S. Tonchev

The present review is devoted to the problems of finite-size scaling due to the presence of long-range interaction decaying at large distance as , where is the spati…

cond-mat.stat-mech2003

The black-body radiation in Tsallis statistics

H. Chamati, A. Ts. Djankova, N. S. Tonchev

Some results for the black-body radiation obtained in the context of the -thermostatistics are analyzed on both thermodynamical and statistical-mechanical levels. Since the ther…

cond-mat.stat-mech2000

Some new exact critical-point amplitudes

H. Chamati, D. M. Danchev, N. S. Tonchev

The scaling properties of the free energy and some of universal amplitudes of a group of models belonging to the universality class of the quantum nonlinear sigma model and the O(n…