Published in Journal of Physics A: Mathematical and Theoretical
When simulating the time evolution of quantum many-body systems on a digital quantum computer, one faces the challenges of quantum noise and of the Trotter error due to time discretization. For certain spin chains, it is possible to discretize the time evolution preserving integrability, so that an extensive set of conserved charges are exactly con...
Published in Journal of Physics A: Mathematical and Theoretical
We consider PT -symmetric ring-like arrays of optical waveguides with purely nonlinear gain and loss. Regardless of the value of the gain–loss coefficient, these systems are protected from spontaneous PT -symmetry breaking. If the nonhermitian part of the array matrix has cross-compensating structure, the total power in such a system remains bounde...
Published in Journal of Physics A: Mathematical and Theoretical
We have developed a quantum-quasiclassical computational scheme for quantitative treating of the nonseparable quantum–classical dynamics of the 6D hydrogen atom in a strong laser pulse. In this approach, the electron is treated quantum mechanically and the center-of-mass (CM) motion classically. Thus, the Schrödinger equation for the electron and t...
Published in Journal of Physics A: Mathematical and Theoretical
The phenomena of flow separation on a surface of finite length is analogous to boundary layer flows caused by retarded motion of continuous surfaces, which ultimately seize at some downstream position and increase drag on aerodynamic vehicles. According to the literature, a stationary surface of finite length will generate a boundary layer that is ...
Published in Journal of Physics A: Mathematical and Theoretical
The intermediate long wave (ILW) hierarchy and its generalization, labelled by a positive integer N, can be formulated as reductions of the lattice KP hierarchy. The integrability of the lattice KP hierarchy is inherited by these reduced systems. In particular, all solutions can be captured by a factorization problem of difference operators. A spec...
Published in Journal of Physics A: Mathematical and Theoretical
We investigate the survival probability of a particle diffusing between two parallel reflecting planes toward a periodic array of absorbing pillars. We approximate the periodic cell of this system by a cylindrical tube containing a single pillar. Using a mode matching method, we obtain an exact solution of the modified Helmholtz equation in this do...
Published in Journal of Physics A: Mathematical and Theoretical
The three-leg cluster method is a relatively new approach to computing the percolation thresholds. To date, it has only been applied to lattice models. It is characterized by high versatility in choosing the shape of the system and by the universal probability 1/2 that, at the phase transition, a three-leg cluster exists that spans three segments o...
Published in Journal of Physics A: Mathematical and Theoretical
We show that the moving energies of some well-known nonholonomic systems are hidden among the first integrals that can be obtained by applying Noether’s first Theorem to a suitable Lagrangian.
Published in Journal of Physics A: Mathematical and Theoretical
Measurement incompatibility is one of the cornerstones of quantum theory. This phenomenon appears in many forms, of which the concept of non-joint measurability has received considerable attention in the recent years. In order to characterise this non-classical phenomenon, various analytical and numerical methods have been developed. The analytical...
Published in Journal of Physics A: Mathematical and Theoretical
The tensor network representation of the ground state of a Bethe chain is analytically obtained and studied in relation to its entanglement distribution. Block entanglement displays a maximum at the interplay between single- and many-bodyness. In systems of two fermions, tensor networks describing states with substantial many-body entropy cannot be...
