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A. V. Nikulov

Publications and source records attributed to A. V. Nikulov.

At least 37 records · Page 2Linked to original sources
arXiv2012

The Meissner effect puzzle and the quantum force in superconductor

The puzzle of the acceleration of the mobile charge carriers and the ions in the superconductor in direction opposite to the electromagnetic force revealed formerly in the Meissner effect is considered in the case of the transition of a narrow ring from normal to superconducting state. It is elucidated that the azimuthal quantum force was deduced eleven years ago from the experimental evidence of this acceleration but it can not solve this puzzle. This quantum force explains other paradoxical phenomena connected with reiterated switching of the ring between normal and superconducting states.

cond-mat.supr-con↗
arXiv2012

A possibility of persistent voltage observation in a system of asymmetric superconducting rings

A possibility to observe the persistent voltage in a superconducting ring of different widths of the arms is experimentally investigated. It was earlier found that switching of the arms between superconducting and normal states by ac current induces the dc voltage oscillation in magnetic field with a period corresponding to the flux quantum inside the ring. We use systems with a large number of asymmetric rings connected in series in order to investigate the possibility to observe this quantum phenomenon near the superconducting transition where thermal fluctuations switch ring segments without external influence and the persistent current is much smaller than in the superconducting state.

cond-mat.supr-con↗
arXiv2011

Segment of an inhomogeneous mesoscopic loop as a dc power source

A dc voltage changed periodically with magnetic field is observed on segments of asymmetric aluminum loop without any external dc current at temperatures corresponded to superconducting transition. According to this experimental result a segment of the loop is a dc power source. A possibility of a persistent voltage on segments of an inhomogeneous normal metal mesoscopic loop follows from this result.

cond-mat.supr-con↗
arXiv2011

Multiple Current States of Two Phase-Coupled Superconducting Rings

The states of two phase-coupled superconducting rings have been investigated. Multiple current states have been revealed in the dependence of the critical current on the magnetic field. The performed calculations of the critical currents and energy states in a magnetic field have made it possible to interpret the experiment as the measurement of energy states into which the system comes with different probabilities because of the equilibrium and non-equilibrium noises upon the transition from the resistive state to the superconducting state during the measurement of the critical current

cond-mat.supr-con↗
arXiv2011

What is the azimuthal quantum force in superconductor

J.E. Hirsch notes in the recent paper arXiv: 0908.409 that the azimuthal quantum force, introduced ten years ago, would violate the principle of angular momentum conservation. It is specified in the present work that the essence and the method of logical deduction of the quantum force do not overstep the limits of the universally recognised quantum formalism. The puzzle revealed by J.E. Hirsch concerns rather of quantum mechanics in whole than a certain theory or work. The essence of this and other puzzles generated with quantum mechanics is considered shortly.

cond-mat.supr-con↗
arXiv2011

Experimental investigations of the change with magnetic flux of quantum number in superconducting ring

The magnetic dependencies of the critical current of aluminum ring with asymmetric link-up of current leads have been measured in order to clear up the essence of the paradoxical absence of the jump of the critical current at the quantum number change revealed before at the measurements of asymmetric superconducting ring. The measurements have shown that the experimental and theoretical dependencies agree in the region of magnetic field corresponding to integer numbers of the flux quantum and disagree at the half of the flux quantum. The jump is not observed as well as in the asymmetric rings.

cond-mat.supr-con↗
arXiv2010

The fundamental obscurity in quantum mechanics. Could the problem be considered universal?

The contemporary controversy about the fundamental obscurity in quantum mechanics keeps on the old one about the aim of science, which was between the founders of the quantum theory. The orthodox quantum mechanics could be created only at the cost of renunciation of reality as the aim of natural science. The description only of phenomena, i.e. results of observation, should not be universal if no one believes that these phenomena are manifestation of a unique reality. Such belief concerning quantum mechanics is quite unacceptable because of irremediably conflict with special relativity. Nevertheless the quantum mechanics was developed and apprehended by most physicists as a universal theory of a quantum world. This fundamental discrepancy between the essence of the orthodox quantum mechanics and its history of development and studying has resulted both to an illusion about the aim of its description among most physicists and to the consideration of its fundamental obscurity as a universal problem among experts in quantum foundation. The aim of this paper is to show that quantum phenomena can not be described universally. It is indicated that rather the Schrodinger's than Born's interpretation of the wave function is valid for description of many quantum phenomena. The fundamental obscurity with which we are faced at the description, for example, macroscopic quantum phenomena differs fundamentally from the one with which the founders of the quantum theory were faced on atomic level.

quant-ph↗
arXiv2010

Contradiction between the results of observations of resistance and critical current quantum oscillations in asymmetric superconducting rings

Magnetic field dependences of critical current, resistance, and rectified voltage of asymmetric (half circles of different widths) and symmetrical (half circles of equal widths) aluminum rings were measured in the temperature region close to the superconducting transition. All these dependences are periodic magnetic field functions with periods corresponding to the flux quantum in the ring. The periodic dependences of critical current measured in opposite directions were found to be close to each other for symmetrical rings and shifted with respect to each other by half the flux quantum in asymmetric rings with ratios between half circle widths of from 1.25 to 2. This shift of the dependences by a quarter of the flux quantum as the ring becomes asymmetric makes critical current anisotropic, which explains the rectification effect observed for asymmetric rings. Shifts of the extrema of the periodic dependences of critical current by a quarter of the flux quantum contradict directly to the results obtained by measuring asymmetric ring resistance oscillations, whose extrema are, as for symmetrical rings, observed at magnetic fluxes equal to an integer and a half of flux quanta.

cond-mat.supr-con↗
arXiv2010

It is needed to shout "wake up"

It is manifested that the disregard of the epistemological problems connected with the fundamental obscurity in quantum mechanics results to the misunderstanding of the essence of this positivistic theory and to both funny and grandiose mistakes of contemporary publications. Some examples of these mistakes are considered.

physics.gen-ph↗
arXiv2010

Quantum computation and hidden variables

Many physicists limit oneself to an instrumentalist description of quantum phenomena and ignore the problems of foundation and interpretation of quantum mechanics. This instrumentalist approach results to "specialization barbarism" and mass delusion concerning the problem, how a quantum computer can be made. The idea of quantum computation can be described within the limits of quantum formalism. But in order to understand how this idea can be put into practice one should realize the question: "What could the quantum formalism describe?", in spite of the absence of an universally recognized answer. Only a realization of this question and the undecided problem of quantum foundations allows to see in which quantum systems the superposition and EPR correlation could be expected. Because of the "specialization barbarism" many authors are sure that Bell proved full impossibility of any hidden-variables interpretation. Therefore it is important to emphasize that in reality Bell has restricted to validity limits of the no- hidden-variables proof and has shown that two-state quantum system can be described by hidden variables. The later means that no experimental result obtained on two-state quantum system can prove the existence of superposition and violation of the realism. One should not assume before unambiguous experimental evidence that any two-state quantum system is quantum bit. No experimental evidence of superposition of macroscopically distinct quantum states and of a quantum bit on base of superconductor structure was obtained for the present. Moreover same experimental results can not be described in the limits of the quantum formalism.

physics.gen-ph↗
arXiv2010

Comment on "Coherent Detection of Electron Dephasing'' [arXiv:0909.2197]

It is shown that the theoretical result according to which electrons can be reflected because of magnetic flux in the Aharonov-Bohm ring contradicts to the fundamental law of momentum conservation and can not conform with the Aharonov-Bohm effect. Therefore a publication of Phys. Rev. Lett. [arXiv:0909.2197] based on this result can not be correct.

physics.gen-ph↗
arXiv2010

Discrete spectrum of measured parameters of a superconductor nanostructure

The discreteness of permitted state spectrum postulated on atomic level can be macroscopic in nanostructures and larger structures because of macroscopic quantum phenomena such as superconductivity. The change by jump of measured parameters because of the macroscopic discreteness may be used for some applications. A device is proposed measured parameters of which can change by jump at a weak change of external parameters. The devise consists of two superconductor loop connected with two Josephson junctions. The macroscopic parameter - maximum value of the super-current through the two Josephson junctions - can change with the quantum number determining macroscopic angular momentum of superconducting pairs in one of the two loops.

cond-mat.supr-con↗
arXiv2010

Could dissipationless current be observed at non-zero resistance?

The persistent current, i.e. the equilibrium direct electric current circulating in realistic rings, some authors interpreted as dissipationless in spite of non-zero resistance of the rings, whereas the other one suppose that this current can not decay at dissipation. The observation of potential difference connected with the persistent current may give new important information about paradoxical nature of this quantum phenomena observed in nanostructures.

cond-mat.supr-con↗
arXiv2010

Could nanostructure be unspeakable quantum system?

Heisenberg, Bohr and others were forced to renounce on the description of the objective reality as the aim of physics because of the paradoxical quantum phenomena observed on the atomic level. The contemporary quantum mechanics created on the base of their positivism point of view must divide the world into speakable apparatus which amplifies microscopic events to macroscopic consequences and unspeakable quantum system. Examination of the quantum phenomena corroborates the confidence expressed by creators of quantum theory that the renunciation of realism should not apply on our everyday macroscopic world. Nanostructures may be considered for the present as a boundary of realistic description for all phenomena including the quantum one.

physics.gen-ph↗
arXiv2010

Flux-qubit and the law of angular momentum conservation

The confidence of many authors in the possibility to use superconducting loop interrupted by Josephson junctions as a basis for quantum bit, flux qubit, presumes the assumption on superposition of two macroscopically distinct quantum states with macroscopically different angular momentum. The contradiction of this assumption with macroscopic realism and the conservation law must call the numerous publications about flux qubit in question. These publications uncover misunderstanding by many modern physicists of the essence of the superposition principle. The Einstein - Podolsky - Rosen (EPR) correlation or entanglement, introduced in 1935 by opponents of the Copenhagen interpretation in order to reveal the contradiction of this principle with realism, has provided a basis of the idea of quantum computation. The problem of the EPR correlation has emerged thanks to philosophical controversy between the creators of the quantum theory about the subject of its description. Therefore it is impossible to solve correctly the problem of quantum computer creation without the insight into the essence of this philosophical controversy. The total neglect of the philosophical problems of quantum foundation results to concrete mistakes, the example of which are the publications about flux qubit. In order to prevent such mistakes in the future the philosophical questions about the essence of superposition and entanglement and about the subject of quantum description are considered.

physics.gen-ph↗
arXiv2010

Weak dissipation does not result in disappearance of persistent current

Experimental results obtained last years corroborate a prediction made by I.O. Kulik forty years ago that the energy dissipation does not result in disappearance of equilibrium circular current observable in the normal state of superconductor rings and normal metal rings. Contrary interpretations of the persistent current as a Brownian motion or a dissipationless current are compared in the point of view of the observations of this phenomenon at presence of an electric potential difference. Distinctions between the quantum phenomena at atomic and mesoscopic levels are accentuated. In connection of the quantum oscillations in magnetic field of potential difference observed on asymmetric rings with the persistent current, it is pointed out that an experimental check of such phenomenon at thermodynamic equilibrium is possible.

cond-mat.supr-con↗