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## Disentangled Quantum Operation on Majorana Qubits in Qubit Chains

Journal of Experimental and Theoretical Physics. 2019. Vol. 129. No. 4. P. 733-737.

We consider quantum logical gates on Majorana qubits implemented in chain structures of ordinary qubits, spins, or pseudospins. We demonstrate that one can implement a two-qubit operation via local manipulations, using an extra coupler spin in a *T*-junction geometry, so that this coupler spin remains disentangled from the qubit. Furthermore, we identify a set of symmetry operations, which not only allow us to determine the resulting two-qubit gate, but also to demonstrate robustness of the resulting gate to inaccuracies in the manipulations, known for topological quantum computation.

Publication based on the results of:

Денисенко М. В., Кленов Н. В., Сатанин А. М., Journal of Physics: Conference Series 2018 Vol. 1124 P. 051027-1-051027-5

Simulation of the entangled (Bell) states generation of two qubits by using of unipolar picoseconds pulses was performed. As an example, a system of two coupled superconducting flux qubits interacting with fluxons that integrated with a Josephson transmission line has been considered. The influence of the pulse shape and quantum noise on the accuracy of ...

Added: February 21, 2019

Денисенко М., Кленов Н., Сатанин А. М., Журнал экспериментальной и теоретической физики 2019 Т. 155 № 2 С. 258-276

Обсуждается задача об ускорении квантовых вычислений путем управления состояниями кубитов короткими униполярными импульсами с большой амплитудой. Предложен новый метод описания динамики кубитов, основанный на представлении Магнуса для оператора эволюции (пропагатора) кубитов, которое позволяет найти решение задачи квантового контроля вне рамок теории возмущений. Эволюция состояний многокубитной системы представлена как движение на специальной унитарной группе SU(N), подобное ...

Added: February 21, 2019

Pino M., Tsvelik A. M., Ioffe L., Physical Review Letters 2015 Vol. 115 P. 197001

Added: October 21, 2016

Mäkinen J. T., Дмитриев В. В., Nissinen J. et al., Nature Communications 2019 Vol. 10 P. 237-1-237-8

Symmetries of the physical world have guided formulation of fundamental laws, including relativistic quantum field theory and understanding of possible states of matter. Topological defects (TDs) often control the universal behavior of macroscopic quantum systems, while topology and broken symmetries determine allowed TDs. Taking advantage of the symmetry-breaking patterns in the phase diagram of nanoconfined ...

Added: January 22, 2019

Шапиро Д. С., Погосов В. В., Lozovik Y., Physical Review A: Atomic, Molecular, and Optical physics 2020 Vol. 102 No. 2 Article 023703

In view of recent proposals for the realization of anisotropic light-matter interaction in such platforms as (i) nonstationary or inductively and capacitively coupled superconducting qubits, (ii) atoms in crossed fields, and (iii) semiconductor heterostructures with spin-orbital interaction, the concept of a generalized Dicke model, where coupling strengths of rotating wave and counter-rotating wave terms are ...

Added: October 31, 2021

Шапиро Д. С., Lozovik Y., Погосов В. В. et al., Physical Review A: Atomic, Molecular, and Optical physics 2019 Vol. 99 No. 6 P. 063821

The analysis of single-mode photon fluctuations and their counting statistics at the superradiant phase transition is presented. The study concerns the equilibrium Dicke model in a regime where the Rabi frequency, related to a coupling of the photon mode with a finite-number qubit environment, plays the role of the transition's control parameter. We use the ...

Added: November 25, 2019

Kolokolov I., Lebedev V., Chertkov M. et al., Journal of Lightwave Technology 2004 Vol. 22 No. 4 P. 1155-1168

This paper presents a method that allows evaluating the performance of an optical fiber system where bit errors result from a complex interplay of spontaneous noise generated in optical amplifiers and birefringent disorder of the transmission fiber. We demonstrate that in the presence of temporal fluctuations of birefringence characteristics, the bit-error rate (BER) itself is ...

Added: February 23, 2017

Nagaev K., Маношин А. А., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 Article 155411

We calculate the electrical and thermal conductivity of a two-dimensional electron gas with strong spin-orbit
coupling in which the scattering is dominated by electron-electron collisions. Despite the apparent absence of
Galilean invariance in the system, the two-particle scattering does not affect the electrical conductivity above
the band-crossing point where both helicity bands are filled. Below the band-crossing point ...

Added: October 14, 2021

Lozovik Y., Огарков С. Л., Sokolik A. A., Physical Review B: Condensed Matter and Materials Physics 2012 Vol. 86 No. 04-5429 P. 1-6

Condensation of pairs formed by spatially separated electrons and holes in a system of two isolated graphene layers is studied beyond the mean-field approximation. Suppression of the screening of the pairing interaction at large distances, caused by the appearance of the gap, is considered self-consistently. A mutual positive feedback between the appearance of the gap ...

Added: March 14, 2013

Загорский Д. Л., Долуденко И., Каневский В. М. et al., Известия РАН. Серия физическая 2021 Т. 85 № 8 С. 1088-1094

FeCo and FeNi alloyed nanowires (NW) were obtained by the matrix synthesis method: the effect of the
growth voltage and the effect of using a reference electrode were studied. It is shown that the composition of
FeNi nanowires strongly depends on the growth potential (with its increase, the bcc structure is changing into
fcc), and it is also ...

Added: November 12, 2021

Ружицкая Д. Д., САМОЙЛЕНКО А. А., Иванов А. Д. et al., Optoelectronics, Instrumentation and Data Processing 2017 Vol. 54 No. 1 P. 1-8

This paper presents an algorithm for processing the transmission spectra of whisperinggallery optical microcavities for use as a nanoparticle detector. The algorithm is based on the broadening of the microcavity resonance curve during precipitation of nanoparticles on the microcavity surface. Experimental results on the detection of particles are compared with Langmuir adsorption theory. The contribution ...

Added: May 25, 2018

Alfimov M., Litvinov A., Journal of High Energy Physics 2022 No. 01 Article 43

We study regularization scheme dependence of beta-function for sigma models with two-dimensional target space. Working within four-loop approximation, we conjecture the scheme in which the beta-function retains only two tensor structures up to certain terms containing zeta_3. Using this scheme, we provide explicit solutions to RG flow equation corresponding to Yang-Baxter- and lambda-deformed SU(2)/U(1) sigma ...

Added: February 1, 2022

Kagan M., JETP Letters 2016 Vol. 103 No. 11 P. 728-738

In this short review, we first discuss the results, which are mainly devoted to the generalizations of the famous Kohn–Luttinger mechanism of superconductivity in purely repulsive fermion systems at low electron densities. In the context of repulsive-U Hubbard model and Shubin–Vonsovsky model we consider briefly the superconducting phase diagrams and the symmetries of the order parameter ...

Added: November 18, 2016

Terekhovich V., Эпистемология и философия науки 2019 Т. 56 № 1 С. 169-184

The framework of simple opposition realism - anti-realism is not enough to analyze the views on the reality of unobservable objects of quantum theory. First, it is necessary to distinguish between realism in relation to the theory and realism in relation to the theory’s objects. Secondly, realism in relation to classical objects can be combined, ...

Added: February 12, 2020

Kuzmichev S. A., Kuzmicheva T. E., Tchesnokov S. et al., Journal of Superconductivity and Novel Magnetism 2016 Vol. 29 No. 4 P. 1111-1116

We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB2. The experimental L,S(T ) are wellfitted with a two-gap model based on Moskalenko and Suhl system of equations (supplemented with a BCS integral renormalization). From the fitting procedure, we estimate the key ...

Added: March 19, 2016

М.: National Instruments Russia, 2017

Содержание сборника составляют доклады с результатами оригинальных исследований и технических решений, ранее не публиковавшиеся. Мы надеемся, что предлагаемый сборник окажется полезным для специалистов, работающих в различных областях науки и техники, для широкого круга преподавателей, аспирантов и студентов ВУЗов, а также для преподавателей средних школ и технических колледжей. ...

Added: May 10, 2017

Maslov V., Russian Journal of Mathematical Physics 2019 Vol. 26 No. 2 P. 168-173

The parameters of unstable short-living isotopes are studied from
the mathematical point of view. The values of the chemical potential
and activity parameters that determine the neutron halo arising when
the neutron separates from the nucleus of an unstable isotope are
calculated. The analogy between nuclear physics and economics is
considered from the point of view of such parameters as ...

Added: August 25, 2019

Morozov I., Norman G., Insepov Z. et al., Physical Review Special Topics - Accelerators and Beams 2012 Vol. 15 P. 053501

This paper describes the surface environment of the dense plasma arcs that damage rf accelerators, tokamaks, and other high gradient structures. We simulate the dense, nonideal plasma sheath near a metallic surface using molecular dynamics (MD) to evaluate sheaths in the non-Debye region for high density, low temperature plasmas. We use direct two-component MD simulations ...

Added: October 28, 2013

Kolokolov I., Lebedev V., Sizov G., Journal of Experimental and Theoretical Physics 2011 Vol. 140 No. 2 P. 387-400

We analyze magnetic kinematic dynamo in a conducting fluid where the stationary shear flow is accompanied by relatively weak random velocity fluctuations. The diffusionless and diffusion regimes are described. The growth rates of the magnetic field moments are related to the statistical characteristics of the flow describing divergence of the Lagrangian trajectories. The magnetic field ...

Added: February 2, 2017

Orekhov M., Russian Journal of Physical Chemistry A 2021 Vol. 95 P. 2059-2064

Molecular dynamic models are created for properties of bivalent ions in organic solvents. It is shown that molecules of the considered solvents bound to ions via oxygen atoms. A theoretical model is developed that describes the ion coordination number. The coordination number in this model is determined by the ratio between the sizes of the ...

Added: October 14, 2021

M.: Faculty of Physics, MSU, 2017

The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. The aim of these conferences is to exchange information and views among the members of the international scientific community in the general field of Low Temperature Physics. It ...

Added: October 1, 2017

Maslov V., Теоретическая и математическая физика 2019 Т. 201 № 1 С. 65-83

We study the process of a nucleon separating from an atomic nucleus from the mathematical standpoint
using experimental values of the binding energy for the nucleus of the given substance. A nucleon becomes
a boson at the instant of separating from a fermionic nucleus. We study the further transformations of
boson and fermion states of separation in a ...

Added: November 1, 2019

Min N., Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18

Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...

Added: November 16, 2020

Kugel K., Bianconi A., Poccia N. et al., Superconductor Science and Technology 2015 Vol. 28 No. 2 P. 024005-1-024005-8

The arrested nanoscale phase separation in a two-band Hubbard model for strongly correlated charge carriers is shown to occur in a particular range in the vicinity of the topological Lifshitz transition, where the Fermi energy crosses the bottom of the narrow band and a new sheet of the Fermi surface related to the charge carriers ...

Added: March 12, 2016