Hysteresis and Post Walrasian Economics

Macroeconomics, hysteresis The “new consensus” dsge (dynamic stochastic general equilibrium) macroeconomic model has microfoundations provided by a single representative agent. In this model shocks to the economic environment do not have any lasting effects. In reality adjustments at the micro level are made by heterogeneous agents, and the aggregation problem cannot be assumed away. In this paper we show that the discontinuous adjustments made by heterogeneous agents at the micro level mean that shocks have lasting effects, aggregate variables containing a selective, erasable memory of the shocks experienced. This hysteresis framework provides foundations for the post-Walrasian analysis of macroeconomic systems

Studying the fidelity of quantum memory based on control-field angular scanning

The fidelity of multimode cavity-assisted quantum storage based on control-field angular scanning is analysed as a function of an input pulse temporal shape, direction of propagation of the control field and spatial structure of the signal field. It is shown by numerical simulation that available range of the angular scanning is reduced with increasing the transverse mode index of the field to be stored. Outside of this range, the output field may contain contributions from undesirable transverse modes due to the cross-talk, which results in reducing efficiency and fidelity. © Published under licence by IOP Publishing Ltd

Optical vector network analysis of ultra-narrow transitions in 166^{166}Er3+^{3+}:7^7LiYF4_4

We present optical vector network analysis (OVNA) of an isotopically purified $^{166}$Er$^{3+}$:$^7$LiYF$_4$ crystal. The OVNA method is based on generation and detection of modulated optical sideband by using a radio-frequency vector network analyzer. This technique is widely used in the field of microwave photonics for the characterization of optical responses of optical devices such as filters and high-Q resonators. However, dense solid-state atomic ensembles induce a large phase shift on one of the optical sidebands which results in the appearance of extra features on the measured transmission response. We present a simple theoretical model which accurately describes the observed spectra and helps to reconstruct the absorption profile of a solid-state atomic ensemble as well as corresponding change of the refractive index in the vicinity of atomic resonances.Comment: 4 pages, 5 figure

Modeling of ambient glutamate concentration measurement in the mammalian nervous system

There exists a big discrepancy between two existing methods of measuring the ambient glutamate concentration in the mammalian (human in particular) nervous system. This work focuses on the construction of a mathematical model that describes these techniques and explains the 100-fold difference in their measurements

Coherent control of collective spontaneous emission in an extended atomic ensemble and quantum storage

Coherent control of collective spontaneous emission in an extended atomic ensemble resonantly interacting with single-photon wave packets is analyzed. A scheme for coherent manipulation of collective atomic states is developed such that superradiant states of the atomic system can be converted into subradiant ones and vice versa. Possible applications of such a scheme for optical quantum state storage and single-photon wave packet shaping are discussed. It is shown that also in the absence of inhomogeneous broadening of the resonant line, single-photon wave packets with arbitrary pulse shape may be recorded as a subradiant state and reconstructed even although the duration of the wave packets is larger than the superradiant life-time. Specifically the applicability for storing time-bin qubits, which are used in quantum cryptography is analyzed.Comment: 11 pages, 4 figures, submitted to PR

Morphological Features of Mountain Maple (Acer Spicatum Lam.) in the R.I. Schroeder Arboretum

В статье приводится описание ползучих побегов клёна колосистого (Acer spicatum Lam.), обнаруженных в дендрарии имени Р.И. Шредера. Помимо раскопки побегов и их осмотра, были сделаны фотографии, на одной из которых для иллюстрации статьи побеги были дополнительно выделены в графическом редакторе. По итогам исследования были сделаны выводы о том, что изучаемый вид склонен в некоторых условиях образовывать длинные ползучие укореняющиеся побеги, располагающиеся как над, так и под землёй, с ответвляющимися вертикальными стволами. Выявленные морфологические особенности представляют интерес для дальнейшего изучения.The article describes the creeping shoots of a spiky maple (Acer spicatum Lam.) found in the R.I. Schroeder Arboretum. In addition to excavating the shoots and examining them, photographs were taken, one of which was further highlighted in a graphic editor to illustrate the article. As a result of the study, it was concluded that the species studied tends to form in some conditions long creeping rooting shoots located both above and below the ground, with branching vertical stems. The morphological features identified are of interest for further study

Atomic frequency comb memory in an isotopically pure 143Nd3+:Y7LiF4 crystal

© 2016 Astro Ltd. We implemented the atomic frequency comb protocol for optical quantum memory in an isotopically pure crystal of Y7LiF4 doped by 143Nd3+ ions. Echo signals were observed on the 4I9/2(1)-4F3/2(1) transition, which had inhomogeneous broadening much smaller than the hyperfine splitting of the ground and excited states. We performed hole-burning spectroscopy measurements on several transitions, obtaining information about the hyperfine state lifetimes. An intrinsic hole structure was found on some of the transitions, which allowed us to prepare a comb structure with two clearly defined periods and to observe echo pulses with different time delays

Generation of a wave packet tailored to efficient free space excitation of a single atom

We demonstrate the generation of an optical dipole wave suitable for the process of efficiently coupling single quanta of light and matter in free space. We employ a parabolic mirror for the conversion of a transverse beam mode to a focused dipole wave and show the required spatial and temporal shaping of the mode incident onto the mirror. The results include a proof of principle correction of the parabolic mirror's aberrations. For the application of exciting an atom with a single photon pulse we demonstrate the creation of a suitable temporal pulse envelope. We infer coupling strengths of 89% and success probabilities of up to 87% for the application of exciting a single atom for the current experimental parameters.Comment: to be published in Europ. Phys. J.