Small cosmological constant in seesaw mechanism with breaking down SUSY

The observed small value of cosmological constant can be naturally related with the scale of breaking down supersymmetry in agreement with other evaluations in particle physics.Comment: 12 pages, revtex4 class, 2 eps-figure

Nonlinear dispersion of stationary waves in collisionless plasmas

A nonlinear dispersion of a general stationary wave in collisionless plasma is obtained in a non-differential form from a single-particle oscillation-center Hamiltonian. For electrostatic oscillations in nonmagnetized plasma, considered as a paradigmatic example, the linear dielectric function is generalized, and the trapped particle contribution to the wave frequency shift $\Delta\omega$ is found analytically as a function of the wave amplitude $a$. Smooth distributions yield $\Delta\omega\sim a^{1/2}$, as usual. However, beam-like distributions of trapped electrons result in different power laws, or even a logarithmic nonlinearity, which are derived as asymptotic limits of the same dispersion relation

Single-shot single-gate RF spin readout in silicon

For solid-state spin qubits, single-gate RF readout can help minimise the number of gates required for scale-up to many qubits since the readout sensor can integrate into the existing gates required to manipulate the qubits (Veldhorst 2017, Pakkiam 2018). However, a key requirement for a scalable quantum computer is that we must be capable of resolving the qubit state within single-shot, that is, a single measurement (DiVincenzo 2000). Here we demonstrate single-gate, single-shot readout of a singlet-triplet spin state in silicon, with an average readout fidelity of $82.9\%$ at a $3.3~\text{kHz}$ measurement bandwidth. We use this technique to measure a triplet $T_-$ to singlet $S_0$ relaxation time of $0.62~\text{ms}$ in precision donor quantum dots in silicon. We also show that the use of RF readout does not impact the maximum readout time at zero detuning limited by the $S_0$ to $T_-$ decay, which remained at approximately $2~\text{ms}$. This establishes single-gate sensing as a viable readout method for spin qubits

Adiabatic nonlinear waves with trapped particles: II. Wave dispersion

A general nonlinear dispersion relation is derived in a nondifferential form for an adiabatic sinusoidal Langmuir wave in collisionless plasma, allowing for an arbitrary distribution of trapped electrons. The linear dielectric function is generalized, and the nonlinear kinetic frequency shift $\omega_{\rm NL}$ is found analytically as a function of the wave amplitude $a$. Smooth distributions yield $\omega_{\rm NL} \propto \sqrt{a}$, as usual. However, beam-like distributions of trapped electrons result in different power laws, or even a logarithmic nonlinearity, which are derived as asymptotic limits of the same dispersion relation. Such beams are formed whenever the phase velocity changes, because the trapped distribution is in autoresonance and thus evolves differently from the passing distribution. Hence, even adiabatic $\omega_{\rm NL}(a)$ is generally nonlocal.Comment: submitted together with Papers I and II

Position-momentum-entangled photon pairs in nonlinear waveguides and transmission lines

We analyze the correlation properties of light in nonlinear waveguides and transmission lines, predict the position-momentum realization of the Einstein-Podolsky-Rosen paradox for photon pairs in Kerr-type nonlinear photonic circuits, and we show how two-photon entangled states can be generated and detected

Desenvolvimento de sistema de poupança de energia baseado em bomba de calor

This article describes the structure and the operation of energy-saving systems based on a heat pump with the use of renewable energy sources. Using the method of an experiment three-factor active planning, the response surfaces and their two-dimensional cross sections were constructed in the isolines of the transition process duration and the amount of the energy carrier heat from the the electric heater power. The developed energy-saving systems support the temperature regime of an agricultural object by using solar energy, low-potential and artificial energy sources throughout the year. The developed system (option one), installed in hard-to-reach places at agricultural facilities, is designed to generate thermal energy, electricity, and provides significant energy savings during energy supply. Due to the speed of the electric regulator with solid filler and electric heater, the efficiency of the heat pump is increased, which maintains the microclimate parameters of the agricultural object.Este artículo describe la estructura y el funcionamiento de los sistemas de ahorro de energía basados en una bomba de calor con el uso de fuentes de energía renovables. Utilizando el método de un experimento de planificación activa de tres factores, las superficies de respuesta y sus secciones transversales bidimensionales se construyeron en las isolinas de la duración del proceso de transición y la cantidad de calor del portador de energía de la potencia del calentador eléctrico. Los sistemas de ahorro de energía desarrollados apoyan el régimen de temperatura de un objeto agrícola mediante el uso de energía solar, potencial bajo y fuentes de energía artificial durante todo el año. El sistema desarrollado (opción uno), instalado en lugares de difícil acceso en las instalaciones agrícolas, está diseñado para generar energía térmica, electricidad y proporciona ahorros de energía significativos durante el suministro de energía. Debido a la velocidad del regulador eléctrico con relleno sólido y calentador eléctrico, se incrementa la eficiencia de la bomba de calor, lo que mantiene los parámetros de microclima del objeto agrícola.Este artigo descreve a estrutura e a operação de sistemas de economia de energia baseados em uma bomba de calor com o uso de fontes de energia renováveis. Utilizando o método de um planejamento ativo de três fatores experimentais, as superfícies de resposta e suas seções transversais bidimensionais foram construídas nas isolinhas da duração do processo de transição e na quantidade de calor do portador de energia a partir da potência do aquecedor elétrico. Os sistemas de economia de energia desenvolvidos suportam o regime de temperatura de um objeto agrícola usando energia solar, fontes de energia artificiais e com baixo potencial ao longo do ano. O sistema desenvolvido (opção 1), instalado em locais de difícil acesso em instalações agrícolas, é projetado para gerar energia térmica, eletricidade e proporcionar economias de energia significativas durante o fornecimento de energia. Devido à velocidade do regulador elétrico com enchimento sólido e aquecedor elétrico, a eficiência da bomba de calor é aumentada, o que mantém os parâmetros microclima do objeto agrícola

Excitonic condensation in a symmetric electron-hole bilayer

Using Diffusion Monte Carlo simulations we have investigated the ground state of a symmetric electron-hole bilayer and determined its phase diagram at T=0. We find clear evidence of an excitonic condensate, whose stability however is affected by in-layer electronic correlation. This stabilizes the electron-hole plasma at large values of the density or inter-layer distance, and the Wigner crystal at low density and large distance. We have also estimated pair correlation functions and low order density matrices, to give a microscopic characterization of correlations, as well as to try and estimate the condensate fraction.Comment: 4 pages, 3 figures, 2 table