arXiv subjects

Wojciech Brzezicki

Publications and source records attributed to Wojciech Brzezicki.

56 records · Page 4Linked to original sources

arXiv2008

Quantum Phase Transition in the One-Dimensional XZ Model

We introduce a one-dimensional (1D) XZ model with alternating $σ_i^zσ_{i+1}^z$ and $σ_i^xσ_{i+1}^x$ interactions on even/odd bonds, interpolating between the Ising model and the quantum compass model. We present two ways of its exact solution by: ($i$) mapping to the quantum Ising models, and ($ii$) using fermions with spin 1/2. In certain cases the nearest neighbor pseudospin correlations change discontinuously at the quantum phase transition, where one finds highly degenerate ground state of the 1D compass model.

cond-mat.str-el↗

arXiv2007

Quantum phase transition in the one-dimensional compass model

We introduce a one-dimensional model which interpolates between the Ising model and the quantum compass model with frustrated pseudospin interactions $σ_i^zσ_{i+1}^z$ and $σ_i^xσ_{i+1}^x$, alternating between even/odd bonds, and present its exact solution by mapping to quantum Ising models. We show that the nearest neighbor pseudospin correlations change discontinuosly and indicate divergent correlation length at the first order quantum phase transition. At this transition one finds the disordered ground state of the compass model with high degeneracy $2\times 2^{N/2}$ in the limit of $N\to\infty$.

cond-mat.str-el↗