We demonstrate nonequilibrium steady-state photon transport through a chain of five coupled artificial atoms simulating the driven-dissipative Bose-Hubbard model. Using transmission spectroscopy, we ...show that the system retains many-particle coherence despite being coupled strongly to two open spaces. We find that cross-Kerr interaction between system states allows high-contrast spectroscopic visualization of the emergent energy bands. For vanishing disorder, we observe the transition of the system from the linear to nonlinear regime of photon blockade in excellent agreement with the input-output theory. Finally, we show how controllable disorder introduced to the system suppresses nonlocal photon transmission. We argue that proposed architecture may be applied to analog simulation of many-body Floquet dynamics with even larger arrays of artificial atoms paving an alternative way towards quantum supremacy.
We point out that superconducting quantum computers are prospective for the simulation of the dynamics of spin models far from equilibrium, including nonadiabatic phenomena and quenches. The ...important advantage of these machines is that they are programmable, so that different spin models can be simulated in the same chip, as well as various initial states can be encoded into it in a controllable way. This opens an opportunity to use superconducting quantum computers in studies of fundamental problems of statistical physics such as the absence or presence of thermalization in the free evolution of a closed quantum system depending on the choice of the initial state as well as on the integrability of the model. In the present paper, we performed proof-of-principle digital simulations of two spin models, which are the central spin model and the transverse-field Ising model, using 5- and 16-qubit superconducting quantum computers of the IBM Quantum Experience. We found that these devices are able to reproduce some important consequences of the symmetry of the initial state for the system’s subsequent dynamics, such as the excitation blockade. However, lengths of algorithms are currently limited due to quantum gate errors. We also discuss some heuristic methods which can be used to extract valuable information from the imperfect experimental data.
We propose a realization of two remarkable effects of Dicke physics in quantum simulation of light-matter many-body interactions with artificial quantum systems. These effects are a superradiant ...decay of an ensemble of qubits and the opposite radiation trapping effect. We show that both phenomena coexist in the crossover regime of a 'moderately bad' single-mode cavity coupled to the qubit subsystem. Depending on the type of the initial state and on the presence of multipartite entanglement in it, the dynamical features can be opposite resulting either in the superradiance or in the radiation trapping despite of the fact that the initial state contains the same number of excited qubits. The difference originates from the symmetrical or nonsymmetrical character of the initial wave function of the ensemble, which corresponds to indistinguishable or distinguishable emitters. We argue that a coexistence of both effects can be used in dynamical quantum simulators to demonstrate realization of Dicke physics, effects of multipartite quantum entanglement, as well as quantum interference and thus to deeply probe quantum nature of these artificial quantum systems.
We calculate the frequency-dependent shot noise in the edge states of a two-dimensional topological insulator coupled to a magnetic impurity with spin
S
= 1/2 of arbitrary anisotropy. If the ...anisotropy is absent, the noise is purely thermal at low frequencies, but tends to the Poisson noise of the full current
I
at high frequencies. If the interaction only flips the impurity spin but conserves those of electrons, the noise at high voltages
eV
≫
T
is frequency-independent. Both the noise and the backscattering current
I
bs
saturate at voltageindependent values. Finally, if the Hamiltonian contains all types of non-spin-conserving scattering, the noise at high voltages becomes frequency-dependent again. At low frequencies, its ratio to 2
eI
bs
is larger than 1 and may reach 2 in the limit
I
bs
→0. At high frequencies, it tends to 1.
Implementation of the outputs of intellectual activity related to manufacture of high added value products may be complicated due to the lack of additional resources of industrial enterprises in the ...context of the economy stagnation. The given Integrated Programme is the programme of a complete innovation cycle formed on the basis of the priority scientific and technological areas highlighted in the R&D Strategy. For the successful implementation of the Programme, it is necessary to identify the needs of large enterprises of the operating sector of the economy in high-tech production processes and to coordinate the potential of implementation with scientific organizations.
A technique for the experimental determination of the thermophysical characteristics of inactive aluminophosphate and borosilicate glasses by differential scanning calorimetry (DSC) is proposed and ...tested. The advantages of this measurement technique are shown. For glassy matrices of various compositions, the specific heat capacity and thermal conductivity coefficient are determined. The obtained experimental values make it possible to calculate the thermal conductivity values. The applicability of this method is proved by working with real samples of vitrified high-level waste to study their properties and form a database based on them.
The effects of the drugs naphazoline and filgrastim, upon individual and co-administration, on the course and outcome of combined radiation–mechanical injury were examined in experimental studies in ...mice. In mice exposed to ionizing radiation at LD
50/30
with a subsequent mechanical injury, naphazoline and filgrastim, upon individual administration, reduced the severity of hemapoiesis impairment of the bone marrow and the proliferative activity of hemapoietic cells, contributing to an increase in survival by 20 and 30%, respectively. Co-administration of naphazoline (prophylactically, 15 min preexposure) and filgrastim (over ten days) has a significant protective effect under specified combined injury, characterized by a 50% increase in survival, a reduced postradiational leukopenia severity, increased colony formation, and myelopoiesis.
Abstract
The presence, quality and proper quantity of motor oil ensures smooth operation of propulsion system for the whole service life of transport vehicle. Oil film is formed during pressure feed ...of motor oil to structural elements of combustion engine via oil channels. Not every modern vehicle is equipped with automated oil level control.
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