Phase space methodIn applied mathematics, the phase space method is a technique for constructing and analyzing solutions of dynamical systems, that is, solving time-dependent differential equations. The method consists of first rewriting the equations as a system of differential equations that are first-order in time, by introducing additional variables. The original and the new variables form a vector in the phase space. The solution then becomes a curve in the phase space, parametrized by time. The curve is usually called a trajectory or an orbit.
Observatoire d'ondes gravitationnellesEn astronomie, un observatoire d'ondes gravitationnelles (on parle aussi de détecteur d'ondes gravitationnelles) est un système destiné à détecter et mesurer les ondes gravitationnelles. Un moyen relativement simple d'observer ces ondes est connu sous le nom de barre de Weber : sous l'effet d'une onde gravitationnelle, l'espace-temps se déforme très légèrement. Ainsi, un objet est également déformé - on peut alors déduire l'intensité et la provenance de l'onde.
Quantum master equationA quantum master equation is a generalization of the idea of a master equation. Rather than just a system of differential equations for a set of probabilities (which only constitutes the diagonal elements of a density matrix), quantum master equations are differential equations for the entire density matrix, including off-diagonal elements. A density matrix with only diagonal elements can be modeled as a classical random process, therefore such an "ordinary" master equation is considered classical.
Quantum nondemolition measurementQuantum nondemolition (QND) measurement is a special type of measurement of a quantum system in which the uncertainty of the measured observable does not increase from its measured value during the subsequent normal evolution of the system. This necessarily requires that the measurement process preserves the physical integrity of the measured system, and moreover places requirements on the relationship between the measured observable and the self-Hamiltonian of the system.
Quantum technologyQuantum technology is an emerging field of physics and engineering, encompassing technologies that rely on the properties of quantum mechanics, especially quantum entanglement, quantum superposition, and quantum tunneling. Quantum computing, sensors, cryptography, simulation, measurement, and imaging are all examples of emerging quantum technologies. The development of quantum technology also heavily impacts established fields such as space exploration.
