Ancilla-Assisted Generation of Photons from Vacuum via Time-Modulation of Extracavity Qubit.

We propose a scheme for the generation of photons from a vacuum via time-modulation of a quantum system indirectly coupled to the cavity field through some ancilla quantum subsystem. We consider the simplest case when the modulation is applied to an artificial two-level atom (we call 't-qubit', that can be located even outside the cavity), while the ancilla is a stationary qubit coupled via the dipole interaction both to the cavity and t-qubit. We find that tripartite entangled states with a small number of photons can be generated from the system ground state under resonant modulations, even when the t-qubit is far detuned from both the ancilla and the cavity, provided its bare and modulation frequencies are properly adjusted.

Adiabatic Amplification of Energy and Magnetic Moment of a Charged Particle after the Magnetic Field Inversion.

We study the evolution of the energy and magnetic moment of a quantum charged particle placed in a homogeneous magnetic field, when this field changes its sign adiabatically. We show that after a single magnetic field passage through zero value, the famous adiabatic invariant ratio of energy to frequency is reestablished again, but with a proportionality coefficient higher than in the initial state. The concrete value of this proportionality coefficient depends on the power index of the frequency dependence on time near zero point.

Adiabatic Amplification of the Harmonic Oscillator Energy When the Frequency Passes through Zero.

We study the evolution of the energy of a harmonic oscillator when its frequency slowly varies with time and passes through a zero value. We consider both the classical and quantum descriptions of the system. We show that after a single frequency passage through a zero value, the famous adiabatic invariant ratio of energy to frequency (which does not hold for a zero frequency) is reestablished again, but with the proportionality coefficient dependent on the initial state.

[Comprehensive assessment of the health of students with different state of the musculoskeletal system].

Priority health indices (the morbidity rate, the resistance status, the physical development, the orthopedic status, the level of bone mineralization, functional reserves of the body, health groups) in schoolchildren aged 7-18 years with a different state of the musculoskeletal system (MSS), learning in secondary schools were studied with the aim of the development of prevention programs. The high incidence of MSS diseases was determined to be combined with a high level of overall morbidity rate, on separate classes--with diseases of the nervous, endocrine, digestive systems, increasing with age ofthe student. Comprehensive assessment of health is much worse in schoolchildren with functional MSS diseases, as well as in girls.

Quantum master equations from classical Lagrangians with two stochastic forces.

We show how a large family of master equations, describing quantum Brownian motion of a harmonic oscillator with translationally invariant damping, can be derived within a phenomenological approach, based on the assumption that an environment can be simulated by two classical stochastic forces. This family is determined by three time-dependent correlation functions (besides the frequency and damping coefficients), and it includes as special cases the known master equations, whose dissipative part is bilinear with respect to the operators of coordinate and momentum.