arXiv subjects

Aleix Bou Comas

Publications and source records attributed to Aleix Bou Comas.

3 recordsLinked to original sources

arXiv2024

New approach to designing functional materials for stealth technology: Radar experiment with bilayer absorbers and optimization of the reflection loss

Microwave power absorption by a two-layer system deposited on a metallic surface has been studied in the experimental setup emulating the response to a radar signal. Layers containing hexaferrite and iron powder in a dried paint of thickness under 1mm have been used. The data is analyzed within a theoretical model derived for a bilayer system from the transmission line theory. A good agreement between experimental and theoretical results is found. The advantage of using a bilayer system over a single-layer system has been demonstrated. How the maximum microwave absorption (minimum reflection loss) can be achieved through the optimization of the filling factors and thicknesses of the two layers is shown.

physics.app-ph↗

arXiv2020

Dissipative failure of adiabatic quantum transport as a dynamical phase transition

Entanglement is the central resource in adiabatic quantum transport. Dephasing affects the availability of that resource by biasing trajectories, driving transitions between success and failure. This depletion of entanglement is important for the practical implementation of quantum technologies. We present a new perspective on the failure of adiabatic computation by understanding the failure of adiabatic transport as a dynamical phase transition. These ideas are demonstrated in a toy model of adiabatic quantum transport in a two spin system.

quant-ph↗

arXiv2018

Manipulating Quantum Spins by a Spin-Polarized Current: An Approach Based Upon PT-Symmetric Quantum Mechanics

We propose a quantum processor based upon single-molecule magnets and spin transfer torque described by PT-symmetric quantum mechanics. In recent years PT-symmetric Hamiltonians have been used to obtain stability thresholds of various systems out of equilibrium. One such problem is the magnetization reversal due to the spin transfer torque generated by a spin-polarized current. So far the studies of this problem have mostly focused on a classical limit of a large spin. In this work we are discussing spin tunneling and quantum dynamics of a small spin induced by a spin polarized current within a PT-symmetric theory. This description can be used for manipulating spin qubits by electric currents.

cond-mat.mes-hall↗