Quasilocal Conservation Laws in the Quantum Hirota Model

Extensivity of conservation laws of the quantum Hirota model on a $1+1$ dimensional lattice is considered. This model can be interpreted in terms of an integrable many-body quantum Floquet dynamics. We establish the procedure to generate a continuous family of quasilocal conservation laws from the conserved operators proposed by Faddeev and Volkov. The Hilbert-Schmidt kernel which allows the calculation of inner products of these new conservation laws is explicitly computed. This result has potential applications in quantum quench and transport problems in integrable quantum field theories.Comment: 16 pages, 6 figure

Quasilocal conservation laws from semicyclic irreducible representations of Uq(sl2)U_q(\mathfrak{sl}_2) in XXZXXZ spin-1/21/2 chains

We construct quasilocal conserved charges in the gapless ($|\Delta| \le 1$) regime of the Heisenberg $XXZ$ spin-$1/2$ chain, using semicyclic irreducible representations of $U_q(\mathfrak{sl}_2)$. These representations are characterized by a periodic action of ladder operators, which act as generators of the aforementioned algebra. Unlike previously constructed conserved charges, the new ones do not preserve magnetization, i.e. they do not possess the $U(1)$ symmetry of the Hamiltonian. The possibility of application in relaxation dynamics resulting from $U(1)$-breaking quantum quenches is discussed

Inhomogeneous MPA and exact steady states of boundary driven spin chains at large dissipation

We find novel site-dependent Lax operators in terms of which we demonstrate exact solvability of a dissipatively driven XYZ spin-1/2 chain in the Zeno limit of strong dissipation, with jump operators polarizing the boundary spins in arbitrary directions. We write the corresponding nonequilibrium steady state using an inhomogeneous MPA, where the constituent matrices satisfy a simple set of linear recurrence relations. Although these matrices can be embedded into an infinite-dimensional auxiliary space, we have verified that they cannot be simultaneously put into a tridiagonal form, not even in the case of axially symmetric (XXZ) bulk interactions and general nonlongitudinal boundary dissipation. We expect our results to have further fundamental applications for the construction of nonlocal integrals of motion for the open XYZ model with arbitrary boundary fields, or the eight-vertex model.Comment: 12 pages, 3 figure

Ballistic spin transport in a periodically driven integrable quantum system

We demonstrate ballistic spin transport of an integrable unitary quantum circuit, which can be understood either as a paradigm of an integrable periodically driven (Floquet) spin chain, or as a Trotterized anisotropic ($XXZ$) Heisenberg spin-1/2 model. We construct an analytic family of quasi-local conservation laws that break the spin-reversal symmetry and compute a lower bound on the spin Drude weight which is found to be a fractal function of the anisotropy parameter. Extensive numerical simulations of spin transport suggest that this fractal lower bound is in fact tight.Comment: 5 + 9 pages, 5 + 2 figure

A retrospective study of peritoneal fluids in cows with abdominal disorders

At the Clinic for Ruminants in Ljubljana, an investigation of peritoneal fluid in cows that stretched over 30 years was conducted. A total of 779 cows were studied; 444 had hardware disease, 212 had left abomasal displacement, 98 cows had right abomasal displacement with or without abomasal torsion, and 25 cows had problems with the uterus. Abdominocentesis, macroscopic and microscopic examination of peritoneal fluid (physical appearance, differantion to transudate/exudates, cytological characteristics) offered valuable diagnostic information. On the basis of the results of 779 laboratory examinations, we have come to the conclusion that abdominal fluid is of significant diagnostic, therapeutic and prognostic value for several acute and chronic abdominal diseases.