Spectrum and Dynamics

Stephen J. Gustafson, Israel Michael Sigal

Omar Gustavo Zabaleta, Constancio Miguel Arizmendi

Medium access control (MAC) and efficient spectrum allocation function particularly, are real challenges that wireless communications are facing nowadays and Dynamic Spectrum Access (DSA), enhanced with quantum computation techniques, is the most promising alternative. In such a context, we capitalize quantum games and quantum decisions strengths to design protocols that make classic communications more efficient. That is, we focus on protocols running on quantum devices whose input and output signals are classic. In this work we propose a quantum media access control (QMAC) that allows dynamic and fair spectrum allocation. Particularly, we point to two of the main DSA functions, which are Spectrum Sharing and Spectrum Allocation.

Zheng Zhen-yu, Xueliang Wang, Shu Chen

We study the boundary-dissipated transverse field Ising model described by a Lindblad master equation and exactly solve its Liouvillian spectrum in the whole parameter space. By mapping the Liouvillian into a Su-Schrieffer-Heeger model with imaginary boundary potentials under a parity constraint, we solve the rapidity spectrum analytically and thus construct the Liouvillian spectrum strictly with a parity constraint condition. Our results demonstrate that the Liouvillian spectrum displays four different structures, which are characterized by different numbers of segments. By analyzing the properties of rapidity spectrum, we can determine the phase boundaries between different spectrum structures analytically and prove the Liouvillian gap fulfilling a duality relation in the weak and strong dissipation region. Furthermore, we unveil the existence of a dynamical duality, i.e., the long-time relaxation dynamics exhibits almost the same dynamical behavior in the weak and strong dissipation region as long as the duality relation holds true.

Victor S. Ibáñez

F. De Zela

A powerful numerical algorithm is described for calculating the micromaser spectrum. The method can be extended as a tool for computing the dynamics of the field density matrix which describes the photon field inside the micromaser cavity. An expression for the micromaser spectrum is also discussed, from which the role played by the initial state in the build-up of the spectrum becomes clearly distinguished from the micromaser dynamics.

Jennifer Gold