Paradoxical Magnetic Cooling in a Structural Transition Model
/ Borrmann, P ; Stamerjohanns, H ; Hilf, E R ; Tománek, D
In contrast to the experimentally widely used isentropic demagnetization process for cooling to ultra-low temperatures we examine a particular classical model system that does not cool, but rather heats up with isentropic demagnetization. This system consists of several magnetite particles in a colloidal suspension, and shows the uncommon behavior of disordering structurally while ordering magnetically in an increasing magnetic field. [...]
cond-mat/0009048.-
2001
- Published in : Eur. Phys. J. B: 19 (2001) , pp. 117-119
External link: cond-mat/0009048 PDF
New enhancements to Feynman's path integral for fermions
/ Borrmann, P ; Hilf, E R
We show that the computational effort for the numerical solution of fermionic quantum systems, occurring e.g., in quantum chemistry, solid state physics, field theory in principle grows with less than the square of the particle number for problems stated in one space dimension and with less than the cube of the particle number for problems stated in three space dimensions. [...]
cond-mat/9412113.
-
1994. - 7 p.
Access to fulltext document