Advanced Statistical Physics Exam - 2nd Session

In this work, we have investigated the phase diagram of the ferrimagnetic mixed spin Blume-Capel model with four-spin J 4 and next nearest neighbor J’ interactions on the

For the most general solution [16] non-diagonal solution of the reflection equation [17] for the XXZ spin chain the algebraic Bethe ansatz using the gauge transformation

Set up the Taylor expansion of the Ginzburg-Landau free-energy function around x = 0 and find the critical line on which the coefficient of the quadratic term vanishes and the one

The co-planar spin configurations identified in the previous items are a sub-set of all ground states in this model.. The full manifold of ground states is disordered in the sense

What do you conclude concerning the possibility of having an ordered state at low (but non-vanishing) temperatures and, therefore, a finite temperature phase transition from

We will now calculate the disorder averaged free-energy density of the model defined on the fully-connected graph with the replica method

Explain the Imry-Ma droplet argument that allows one to estimate in which dimension this model can sustain an ordered phase.... Draw an schematic

Give an expression for the difference, ∆E, between the energy of a configuration with one domain wall placed between the sites n and n + 1 and the energy of the ground state (choose