Fast and robust two- and three-qubit swapping gates on multi-atomic ensembles in quantum electrodynamic cavity

Creation of quantum computer is outstanding fundamental and practical problem. The quantum computer could be used for execution of very complicated tasks which are not solvable with the classical computers. The first prototype of solid state quantum computer was created in 2009 with superconducting qubits. However, it suffers from the decoherent processes and it is desirable to find more practical encoding of qubits with long-lived coherence. It could be single impurity or vacancy centers in solids, but their interaction with electromagnetic radiation is rather weak. So, here, ensembles of atoms were proposed for the qubit encoding by using the dipole blockade mechanism in order to turn multilevel systems in two level ones. But dipole-dipole based blockade introduces an additional decoherence that limits its practical significance. Recently, the collective blockade mechanism has been proposed for the system of three-level atoms by using the different frequency shifts for the Raman transitions between the collective atomic states characterized by a different number of the excited atoms. Here, we propose two qubit gate by using another collective blockade mechanism in the system of two level atoms based on exchange interaction via the virtual photons between the multi-atomic ensembles in the resonator. Also we demonstrate the possibility of three qubit gate (Controlled SWAP gate) using a suppression of the swap-process between two multi-atomic ensembles due to dynamical shift of the atomic levels controlled by the states of photon encoded qubit

Pressure dependence of upper critical fields in FeSe single crystals

We investigate the pressure dependence of the upper critical fields ({\mu}$_0$$H$$_{c2}$) for FeSe single crystals with pressure up to 2.57 GPa. The superconducting (SC) properties show a disparate behavior across a critical pressure where the pressure-induced antiferromagnetic phase coexists with superconductivity. The magnetoresistance for $H//ab$ and $H//c$ is very different: for $H//c$, magnetic field induces and enhances a hump in the resistivity close to the $T_c$ for pressures higher than 1.2 GPa, while it is absent for $H//ab$. Since the measured {\mu}$_0$$H$$_{c2}$ for FeSe samples is smaller than the orbital limited upper critical field ($H$$^{orb}$$_{c2}$) estimated by the Werthamer Helfand and Hohenberg (WHH) model, the Maki parameter ({\alpha}) related to Pauli spin-paramagnetic effects is additionally considered to describe the temperature dependence of {\mu}$_0$$H$$_{c2}$($T$). Interestingly, the {\alpha} value is hardly affected by pressure for $H//ab$, while it strongly increases with pressure for $H//c$. The pressure evolution of the {\mu}$_0$$H$$_{c2}$(0)s for the FeSe single crystals is found to be almost similar to that of $T_c$($P$), suggesting that the pressure-induced magnetic order adversely affects the upper critical fields as well as the SC transition temperature.Comment: 23 pages, 6 figures, 1 tabl

Arteriovenous Relationships in the Pathogenesis of Encephalopathy

The study aims at investigating the disturbance in intra- and extracranial interaction of arterial and venous vessels in stable arterial hypertension (SAH) and building a model of vascular relationships in the system: inflow – the exchange field of cerebral blood flow – outflow. Baseline data were obtained by catheterization through a probe that was wedged in the superior bulb of the internal jugular vein, where the hemodynamic and biochemical parameters of cerebral blood flow were obtained. Arterial blood was collected from the thoracic aorta. We performed the correlation and factor analyses of the relationship between the parameters of inflow and outflow to the skull in SAH patients compared with those in the control group. The identified differences led to the following conclusions: There is a loss of homeostatic control for the hemodynamic (extra- and intracerebral) and biochemical regulation in SAH; the high-energy processes of the aortic chamber (systolic and pulse pressure) spread to the bloodstream of the brain; the damping function of carotid siphons is impaired; cerebral venous stasis is formed; increased pressure in the microvascular venous network of the brain is defined; and a loss of the homeostatic control of the rheological properties of blood is defined. The loss of extracranial regulation of intracranial venous pressure in SAH leads to venous plethora of the intracerebral vessels, increasing the “booster" pressure in the microvasculature, and circulatory hypoxia of brain tissues. The consequences of these changes are metabolic and hemodynamic disturbances in energy supply for activated neurons, as well as circulatory hypoxia resulting in disturbances of the regulatory function of the nervous system and mental activity, and the development of hypertonic angioencephalopathy

The Gravity Dual of the Ising Model

We evaluate the partition function of three dimensional theories of gravity in the quantum regime, where the AdS radius is Planck scale and the central charge is of order one. The contribution from the AdS vacuum sector can - with certain assumptions - be computed and equals the vacuum character of a minimal model CFT. The torus partition function is given by a sum over geometries which is finite and computable. For generic values of Newton's constant G and the AdS radius L the result has no Hilbert space interpretation, but in certain cases it agrees with the partition function of a known CFT. For example, the partition function of pure Einstein gravity with G=3L equals that of the Ising model, providing evidence that these theories are dual. We also present somewhat weaker evidence that the 3-state and tricritical Potts models are dual to pure higher spin theories of gravity based on SL(3) and E_6, respectively.Comment: 42 page

A Non-Invasive Method for the Diagnosis of Sjogren's Syndrome with the Evaluation of the Capacity of Salivary Glands

This study describes a non-invasive method for diagnosing Sjogren’s syndrome (SS) with MR sialography, which is based on the contrasting of the ductal system with its own secretion and the possibility of simultaneous assessment of the secretory function of parotid salivary glands (PSG). The objective of this study was to evaluate the effectiveness of MR sialography in the diagnosis of SS and chronic parenchymal sialadenitis. Methods and Results: The study included 60 patients aged between 25 and 70 years with PSG impairments. Inclusion criteria: patients suffering from dry mouth and enlarged PSG, with an established diagnosis of SS and chronic parenchymal sialadenitis. The sensitivity and diagnostic accuracy of MR sialography was 96.6% and 95.2% in the diagnosis of SS, and 94.4% and 93.3% in the diagnosis of chronic parenchymal sialadenitis. Specificity of the method was 91.6%. Conclusion: MR sialography, highly effective and identical to sialography, allows detecting typical disorders in parotid salivary glands that are inherent to Sjogren’s syndrome and chronic parenchymal sialadenitis

Yedoma permafrost genesis: Over 150 years of mystery and controversy

Since the discovery of frozen megafauna carcasses in Northern Siberia and Alaska in the early 1800s, the Yedoma phenomenon has attracted many Arctic explorers and scientists. Exposed along coastal and riverbank bluffs, Yedoma often appears as large masses of ice with some inclusions of sediment. The ground ice particularly mystified geologists and geographers, and they considered sediment within Yedoma exposures to be a secondary and unimportant component. Numerous scientists around the world tried to explain the origin of Yedoma for decades, even though some of them had never seen Yedoma in the field. The origin of massive ice in Yedoma has been attributed to buried surface ice (glaciers, snow, lake ice, and icings), intrusive ice (open system pingo), and finally to ice wedges. Proponents of the last hypothesis found it difficult to explain a vertical extent of ice wedges, which in some cases exceeds 40 m. It took over 150 years of intense debates to understand the process of ice-wedge formation occurring simultaneously (syngenetically) with soil deposition and permafrost aggregation. This understanding was based on observations of the contemporary formation of syngenetic permafrost with ice wedges on the floodplains of Arctic rivers. It initially was concluded that Yedoma was a floodplain deposit, and it took several decades of debates to understand that Yedoma is of polygenetic origin. In this paper, we discuss the history of Yedoma studies from the early 19th century until the 1980s—the period when the main hypotheses of Yedoma origin were debated and developed