This paper presents a simple and effective wideband method for the determination of material properties, such as the complex index of refraction and the complex permittivity and permeability. The method is explicit (non-iterative) and referenceplane invariant: it uses a certain combination of scattering parameters in conjunction with group-velocity data. This technique can be used to characterize both dielectric and magnetic materials. The proposed method is verified experimentally within a frequency range between 2 to 18 GHz on polytetrafluoroethylene and polyvinylchloride samples. A comprehensive error and stability analysis reveals that, similar to other methods based on transmission/reflection measurement, the uncertainties are larger at low frequencies and at the Fabry-Pérot resonances.

Ion processing of the reactive surface of a free-standing polycrystalline metal film induces a flow of atoms into grain boundaries, resulting in plastic deformation. A thorough experimental and theoretical analysis of this process is presented, along with the demonstration of novel engineering concepts for precisely controlled 3D assembly at micro- and nanoscopic scales.

We study analytically and numerically the problem of two qubits with fixed coupling irradiated with quantum or classical fields. In the classical case, we derive an effective Hamiltonian and describe its entangling properties. We identify a coupling/decoupling switching protocol and we construct composite pulse sequences leading to a CNOT gate. In the quantum case, we show that qubit-qubit-photon multiparticle entanglement and maximally entangled two-qubit states can be obtained by driving the system at very low powers (one quanta of excitation). Our results can be applied to a variety of systems of two superconducting qubits coupled to resonators.

Spin-transfer ferromagnetic resonance (ST-FMR) in symmetric magnetic tunnel junctions (MTJs) with a varied thickness of the MgO tunnel barrier (0.75 nm < tMgO < 1.05 nm) is studied using the spin-torque diode effect. The application of an RF current into nanosized MTJs generates a DC mixing voltage across the device when the frequency is in resonance with the resistance oscillations arising from the spin transfer torque. Magnetization precession in the free and reference layers of the MTJs is analyzed by comparing ST-FMR signals with macrospin and micromagnetic simulations. From ST-FMR spectra at different DC bias voltage, the in-plane and perpendicular torkances are derived. The experiments and free-electron model calculations show that the absolute torque values are independent of tunnel barrier thickness. The influence of coupling between the free and reference layer of the MTJs on the ST-FMR signals and the derived torkances are discussed.