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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Вальков, Валерий Владимирович, Аксенов, Сергей Владимирович, Уланов Е. А.
Заглавие : Эффект Фано при туннелировании спин-поляризованного электрона через одиночную магнитную примесь
Место публикации : Физ. низких температур. - 2013. - Т. 39, Вып. 1. - С. 48-52
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Аксенов, Сергей Владимирович, Аксенов, Сергей Владимирович, Уланов Е. А.
Заглавие : Индуцирование спин-флип-процессами резонанса Фано при туннелировании электрона через спиновые структуры атомного масштаба
Место публикации : Журн. эксперим. и теор. физ. - 2013. - Т. 143, Вып. 5. - С. 984-990. - DOI 10.7868/S0044451013050248
Аннотация: Показано, что включение неупругих спин-зависящих процессов рассеяния электрона на потенциальных профилях одиночной магнитной примеси и спинового димера инициирует резонансные особенности, обусловленные эффектом Фано, в транспортных характеристиках таких спиновых структур атомного масштаба. Для реализации резонанса и антирезонанса Фано принципиальную роль играют спин-флип-процессы, приводящие к конфигурационному взаимодействию состояний системы. Установлено, что приложение внешнего магнитного поля и электрического поля затвора позволяет радикально изменять проводящие свойства спиновых структур через резонансный механизм Фано
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mendez-Bermudez J. A., Luna-Acosta G. A., Seba P., Pichugin K. N.
Заглавие : Understanding quantum scattering properties in terms of purely classical dynamics: Two-dimensional open chaotic billiards
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2002. - Vol. 66, Is. 4. - Ст.46207. - ISSN 1539-3755, DOI 10.1103/PhysRevE.66.046207
Примечания : Cited References: 34
Предметные рубрики: BALLISTIC-TRANSPORT
POINCARE SECTIONS
CAVITIES
EIGENFUNCTIONS
LOCALIZATION
CHANNEL
Ключевые слова (''Своб.индексиров.''): chaos theory--electron tunneling--laser applications--nonlinear systems--probability--waveguide components--chaotic motion--microlasers--quantum scattering--scattering probability--quantum theory--article
Аннотация: We study classical and quantum scattering properties of particles in the ballistic regime in two-dimensional chaotic billiards that are models of electron- or micro-waveguides. To this end we construct the purely classical counterparts of the scattering probability (SP) matrix \S(n,m)\(2) and Husimi distributions specializing to the case of mixed chaotic motion (incomplete horseshoe). Comparison between classical and quantum quantities allows us to discover the purely classical dynamical origin of certain general as well as particular features that appear in the quantum description of the system. On the other hand, at certain values of energy the tunneling of the wave function into classically forbidden regions produces striking differences between the classical and quantum quantities. A potential application of this phenomenon in the field of microlasers is discussed briefly. We also see the manifestation of whispering gallery orbits as a self-similar structure in the transmission part of the classical SP matrix.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volkov N. V., Patrin G. S., Petrakovskii G. A., Sablina K. A., Ovchinnikov S. G., Varnakov S. N.
Заглавие : Tunneling magnetoresistance in a Eu0.7Pb0.3MnO3 (single crystal)-Fe (film) structure
Место публикации : Tech. Phys. Lett.: AMER INST PHYSICS, 2003. - Vol. 29, Is. 3. - P200-202. - ISSN 1063-7850, DOI 10.1134/1.1565633
Примечания : Cited References: 7
Аннотация: We have studied the magnetoresistive properties of a structure comprising single crystal manganite Eu0.7Pb0.3MnO3 covered with an epitaxial iron film. At temperatures below T-C of the manganite crystal, the structure exhibits positive magnetoresistance. The behavior of the resistance as a function of the magnetic field is characteristic of a tunneling junction with ferromagnetic electrodes separated by a thin insulating film. The observed effect is related to the formation of a transition layer at the manganite-Fe interface, which is depleted of oxygen and possesses dielectric properties. The sensitivity of the resistance with respect to the magnetic field is determined both by the negative magnetoresistance of the manganite crystal and by the tunneling contribution to the conductivity, whereby the tunneling current depends on the mutual orientation of magnetic moments of the electrodes (Eu0.7Pb0.3MnO3 crystal and Fe film). (C) 2003 MAIK "Nauka/Interperiodica".
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fransson J., Holmstrom E., Eriksson O., Sandalov I.
Заглавие : Theory of spin filtering through quantum dots
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2003. - Vol. 67, Is. 20. - Ст.205310. - ISSN 1098-0121, DOI 10.1103/PhysRevB.67.205310
Примечания : Cited References: 28
Предметные рубрики: DEPENDENT TUNNELING JUNCTIONS
NARROW ENERGY BANDS
ELECTRON CORRELATIONS
MAGNETORESISTANCE
BARRIER
POLARIZATION
Аннотация: Using a nonequilibrium diagram technique for Hubbard operator Green functions combined with a generalization of the transfer Hamiltonian formalism, we calculate the transport through a magnetic quantum dot system with spin-dependent couplings to the contacts. In specific regimes of the parameter space the spin-dependent tunnel current becomes more than 99.95% spin polarized, suggesting that a device thus constructed can be used in spin-filter applications. First-principles electronic structure calculations show the existence of nanostructured systems, such as, e.g., MgO/Fe/Pd(5)/Fe/MgO (001), with the desired properties in the direction of the current.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Karpov S. V., Semina P. N., Gavrilyuk A. P.
Заглавие : The role of the electron tunneling effect in the coagulation kinetics of polydisperse metal nanocolloids
Место публикации : Colloid J.: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 74, Is. 3. - P.305-312. - ISSN 1061-933X, DOI 10.1134/S1061933X12030052
Примечания : Cited References: 16. - Authors are thankful to G. A. Chiganova for discussions and helpful comments. Studies were carried out with the support of grants: the Presidium of RAS No 29 and No 31, OFN RAS III.9.5, IP SB RAS No 43, IP SB RAS (and SFU) No 101.
Предметные рубрики: PARTICLES
Аннотация: The energy of pair interactions between metal nanoparticles of different sizes is shown to be able to increase upon coagulation due to the additional electrostatic effect resulting from mutual heteropolar charging of the particles. The tunnel electron transfer occurring upon the collisions between particles of different sizes may be the reason for the charging. The transfer is caused by the dependence of the electron work function on the particle size. The electron transfer through the interparticle gap equalizes the Fermi levels in particles of different sizes and is associated with this dependence. Using the example of bimodal silver nanocolloids, it is shown that mutual heteropolar charging of particles with different sizes may accelerate the coagulation of polydisperse colloidal systems by an order of magnitude or more as compared with monodisperse systems, in which this effect is absent.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volkov N. V., Eremin E. V., Tsikalov V. S., Patrin G. S., Kim P. D., Yu S. C., Kim D. H., Chau N.
Заглавие : Switching of current channels and new mechanism of magnetoresistance in a tunneling structure
Коллективы : Russian Foundation for Basic Research [08-02-00259, 08-02-100397]; Ministry of Education and Science of the Russian Federation [2.1.1/6038]
Место публикации : Tech. Phys. Lett. - 2009. - Vol. 35, Is. 11. - P.990-993. - ISSN 1063-7850, DOI 10.1134/S1063785009110054
Примечания : Cited References: 7. - This study was supported by the Russian Foundation for Basic Research (project nos. 08-02-00259 and 08-02-100397) and the Ministry of Education and Science of the Russian Federation (program "Development of Scientific Potential of Higher Education 2009-2010," project no. 2.1.1/6038).
Аннотация: We have experimentally studied the transport properties of a planar La(0.7)Sr(0.3)MnO(3) (LSMO)/Mn-depleted LSMO/MnSi tunneling structure, in which the Mn-depleted LSMO layer plays the role of a potential barrier between the conducting layers of LSMO and MnSi. The measurements were performed in geometry with the current direction parallel to the planes of interfaces in the tunneling structure. It is established that the structure exhibits a nonlinear current-voltage characteristic and possesses a positive magnetoresistance, the value of which depends on the tunneling current. It is suggested that specific features of the transport properties of this structure are related to the phenomenon of current channel switching between the conducting layers. The switching mechanism is based on the dependence of the resistance of the tunneling junction between the conducting layers on the bias voltage and the applied magnetic field.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Alekseev K. N., Berman G. P., Campbell D. K.
Заглавие : Strange attractor in resonant tunneling
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 1998. - Vol. 58, Is. 7. - P3954-3962. - ISSN 0163-1829, DOI 10.1103/PhysRevB.58.3954
Примечания : Cited References: 38
Предметные рубрики: INTRINSIC BISTABILITY
RING CAVITY
OPTICAL TURBULENCE
TRANSMITTED LIGHT
QUANTUM-WELLS
OSCILLATIONS
BARRIERS
SYSTEM
STATE
TIME
Аннотация: We consider the process of resonant electron tunneling through a double-barrier potential, taking into account nonlinear dynamical effects generated by charge accumulation in the interbarrier space. We use the perturbation approach of Davydov and Ermakov, which was developed for investigating intrinsic bistability in resonant tunneling. For incoming electron flow, which is modulated slowly in time, we show that the resulting nonlinear dynamics can become chaotic, with the chaos described (because of the open nature of the system) by a strange attractor. We determine the conditions for the existence of this strange attractor and estimate characteristic experimental parameters for its observation.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Aksenov S. V., Ulanov E. A.
Заглавие : Spin-flip induction of Fano resonance upon electron tunneling through atomic-scale spin structures
Место публикации : J. Experim. Theor. Phys.: Springer, 2013. - Vol. 116, Is. 5. - P.854-859. - DOI 10.1134/S1063776113050130
Аннотация: The inclusion of inelastic spin-dependent electron scatterings by the potential profiles of a single magnetic impurity and a spin dimer is shown to induce resonance features due to the Fano effect in the transport characteristics of such atomic-scale spin structures. The spin-flip processes leading to a configuration interaction of the system’s states play a fundamental role for the realization of Fano resonance and antiresonance. It has been established that applying an external magnetic field and a gate electric field allows the conductive properties of spin structures to be changed radically through the Fano resonance mechanism
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zalipaev V. V., Maksimov D. N., Linton C. M., Kusmartsev F. V.
Заглавие : Spectrum of localized states in graphene quantum dots and wires
Место публикации : Phys. Lett. A. - 2013. - Vol. 377, Is. 3-4. - P.216-221. - ISSN 0375-9601, DOI 10.1016/j.physleta.2012.11.028
Ключевые слова (''Своб.индексиров.''): generalized bohr-sommerfeld quantization condition--graphene--high-energy eigenstates--semiclassical approximation--tunneling
Аннотация: We developed semiclassical method and show that any smooth potential in graphene describing elongated a quantum dot or wire may behave as a barrier or as a trapping well or as a double barrier potential, Fabry-Perot structure, for 1D Schrodinger equation. The energy spectrum of quantum wires has been found and compared with numerical simulations. We found that there are two types of localized states, stable and metastable, having finite life time. These life times are calculated, as is the form of the localized wave functions which are exponentially decaying away from the wire in the perpendicular direction. В© 2012 Elsevier B.V. All rights reserved.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Berman G. P., Bulgakov E. N., Campbell D. K., Sadreev A. F.
Заглавие : Resonant tunneling in time-periodically modulated semiconductor nanostructures
Место публикации : Physica B. - 1996. - Vol. 225, Is. 1-2. - P.1-22. - ISSN 0921-4526, DOI 10.1016/0921-4526(96)00233-5
Примечания : Cited References: 39
Предметные рубрики: DOUBLE BARRIERS
TRANSMISSION
HETEROSTRUCTURES
Аннотация: We consider a semiconductor (AlGaAs/GaAs/AlGaAs) double-barrier resonant tunneling nanostructure (DBRTS), in which the bottom of the potential well is modulated by an external periodic potential V(t) = V-mod cos Omega t. We examine the resonance response to both mono-energetic and spatially localized incident electrons, extending previous results in three ways. First, we study numerically the resonant characteristics in the transmission probabilities as functions of both the electron's energy and the frequency of the external field. We find that new low-frequency resonant peaks appear in the frequency dependence of the transmission probabilities and discuss the origin and possible experimental observation of these peaks. Second, we develop an analytic perturbation theory (valid for small values of the parameter lambda = V-mod/h Omega) describing the processes of absorption and emission of single quanta of the modulation field and show that this perturbative treatment agrees well with the results of numerical calculations in the appropriate regions, up to and including the regime in which the one-quantum processes saturate. Third, for localized (Gaussian) incident wave packets, we show numerically that temporal modulations of the potential well in the DBRTS can induce spatial modulations in the transmitted and reflected wave packets. We develop a simple qualitative picture that explains our results. Finally, we estimate characteristic values of the parameters relevant for possible observation of these effects in laboratory experiments.
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12.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Popkov S. I., Shaikhutdinov K. A., Nikitin S. E., Petrov M. I., Terent'yev K. Yu., Semenov S. V.
Заглавие : Positive magnetoresistance of single-crystal bilayer manganites (La1−zNdz)1.4Sr1.6Mn2O7
Коллективы : Euro-Asian Symposium "Trends in MAGnetism", "Trends in MAGnetism", Euro-Asian Symposium, Институт физики им. Л.В. Киренского Сибирского отделения РАН
Место публикации : VI Euro-Asian Symposium "Trends in MAGnetism" (EASTMAG-2016): abstracts/ ed.: O. A. Maksimova, R. D. Ivantsov. - Krasnoyarsk: KIP RAS SB, 2016. - Ст.O4.2. - P.222. - ISBN 978-5-904603-06-9 (Шифр -478014040)
Примечания : References: 4
Ключевые слова (''Своб.индексиров.''): bilayer manganites--positive magnetoresistance--spin-dependent tunneling
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Dubrovskiy A. A., Shaykhutdinov K. A., Popkov S. I., Petrov M. I.
Заглавие : Peculiarities of the time evolution of magnetoresistance of granular HTSC in a constant applied magnetic field
Коллективы :
Место публикации : Solid State Commun. - 2008. - Vol. 147, Is. 7-8. - P.284-287. - ISSN 0038-1098, DOI 10.1016/j.ssc.2008.05.044
Примечания : Cited References: 17. - This work was Supported by program "Quantum macrophysics" No. 3.4 of RAS and integration project No. 3.4 of SB RAS and in part by KSF, grant 18G011. D.A.B. and A.A.D. acknowledge the Russian Science Support Foundation.
Предметные рубрики: CRITICAL-STATE
SUPERCONDUCTORS
COMPOSITES
HYSTERESIS
RESISTANCE
Ключевые слова (''Своб.индексиров.''): superconductors--flux pinning and creep--tunneling--superconductors--flux pinning and creep--tunneling--agricultural products--carbon fiber reinforced plastics--copper oxides--electric conductivity--electric resistance--evolutionary algorithms--ferromagnetism--galvanomagnetic effects--grain (agricultural product)--health--hysteresis--magnetic devices--magnetic field effects--magnetic field measurement--magnetic fields--magnetic materials--magnetoelectronics--magnetoresistance--semiconductor metal boundaries--superconducting magnets--superconductivity--yttrium barium copper oxides--p ,p ,t measurements--applied (co)--applied magnetic fields--constant magnetic field (cmf)--elsevier (co)--evolution (co)--external fields--field induced--flux creep--hysteretic behavior--josephson couplings--low magnetic fields--magnetic (ce)--poly crystalline--superconducting grains--time evolutions--time relaxation--magnetism
Аннотация: The time evolution of the magnetoresistance of bulk YBCO + CuO composites at T = 4.2 K in constant applied magnetic fields was studied to clarify the mechanism of hysteretic behavior of magnetoresistance R(H) of granular HTSC. The composites represent "model" granular HTSC with weakened Josephson coupling between superconducting (YBCO) crystallites. It was found for the first time that on the ascending branch of R(H) dependence, the resistance at H = const decreased with time while on the descending branch, the resistance increased with time in ail applied constant magnetic field. In the range of low magnetic fields (below the minimum point of the descending branch of the R(H) dependence), the resistance at H const decreased again. Similar measurements performed oil pure polycrystalline YBCO at T = 77.4 K have shown that the behavior of evolution of resistance with time is similar to that observed for the composite. This proves the peculiarity of time evolution of maignetoresistance to be a common feature of granular HTSCs. The behavior revealed is well described by the model Of granular HTSC, where the intergrain media is in an effective magnetic field which is the superposition of the external field and the field induced by superconducting grains. The time evolution of resistance reflects the time relaxation of magnetization of HTSC grains due to the intragrain flux Creep Processes. (C) 2008 Elsevier Ltd. All rights reserved.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fransson J., Eriksson O., Johansson B., Sandalov I. S.
Заглавие : On the non-orthogonality problem in the description of quantum devices
Коллективы : International Conference on Nonequilibrium Carrier Dynamics in Semiconductors
Место публикации : Physica B/ International Conference on Nonequilibrium Carrier Dynamics in Semiconductors (11 ; 1999 ; July ; 19-23 ; Kyoto, Japan). - 1999. - Vol. 272, Is. 1-4. - P.28-30. - ISSN 0921-4526, DOI 10.1016/S0921-4526(99)00343-9
Примечания : Cited References: 8
Предметные рубрики:
Ключевые слова (''Своб.индексиров.''): non-orthogonality--current--tunneling--correlation methods--electric contacts--electric currents--electron energy levels--electron tunneling--equations of motion--green's function--mathematical operators--matrix algebra--hubbard operators--potential barriers--tunneling currents--semiconductor quantum dots
Аннотация: An approach which allows to include the corrections from non-orthogonality of electron states in contacts and quantum dots is developed. Comparison of the energy levels and charge distributions of electrons in 1D quantum dot (QD) in equilibrium, obtained within orthogonal (OR) and non-orthogonal representations (NOR), with the exact ones shows that the NOR provides a considerable improvement, for levels below the top of barrier. The approach is extended to non-equilibrium states. A derivation of the tunneling current through a single potential barrier is performed using equations of motion for correlation functions. A formula for transient current derived by means of the diagram technique for Hubbard operators is given for the problem of QD with strongly correlated electrons interacting with electrons in contacts. The non-orthogonality renormalizes the tunneling matrix elements and spectral weights of Green functions. (C) 1999 Elsevier Science B.V. All rights reserved.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kolovsky A. R., Maksimov D. N.
Заглавие : Mott-insulator state of cold atoms in tilted optical lattices: Doublon dynamics and multilevel Landau-Zener tunneling
Место публикации : Phys. Rev. A: American Physical Society, 2016. - Vol. 94, Is. 4. - Ст.043630. - ISSN 10502947 (ISSN), DOI 10.1103/PhysRevA.94.043630
Примечания : Cited References: 34
Ключевые слова (''Своб.индексиров.''): crystal lattices--optical materials--analytical expressions--cold atoms--doublons--dynamical response--in-laboratory experiments--landau zener tunneling--mott insulator state--optical lattices
Аннотация: We discuss the dynamical response of strongly interacting Bose atoms in an adiabatically tilted optical lattice. The analysis is performed in terms of the multilevel Landau-Zener tunneling. Different regimes of tunneling are identified and analytical expressions for the doublon number, which is the quantity measured in laboratory experiments, are derived. © 2016 American Physical Society.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S., Romanova O. B., Янушкевич, Казимир Иосифович
Заглавие : Magnetoresistance effect in anion-substituted manganese chalcogenides
Место публикации : Phys. Status Solidi B. - 2015. - Vol. 252, Is. 8. - P.1792-1798. - ISSN 0370, DOI 10.1002/pssb.201451607. - ISSN 15213951 (eISSN)
Примечания : Cited References: 35. - This study was supported by the official assignment no. 114090470016.
Предметные рубрики: MAGNETIC-PROPERTIES
ELECTRONIC-STRUCTURE
SOLID-SOLUTIONS
MnTe
MnSe
CONDUCTIVITY
TRANSITION
Ключевые слова (''Своб.индексиров.''): electron tunneling--magnetic properties--magnetoresistance--semiconductors
Аннотация: The electric and magnetic properties of anion-substituted antiferromagnetic MnSe1-xTex (0.1≤x≤0.4) semiconductors in the 77-700K temperature range and magnetic fields under 1T are studied. In the MnSe1-xTex solid solutions, negative magnetoresistance in the vicinity of the Néel temperature for x=0.1 and for composition with x=0.2 in the paramagnetic range below 270K is revealed. A dependence of the magnetic susceptibility versus the prehistory of the samples is found. The model of localized spin-polarized electrons with the localization radius depending on the magnetic field is proposed for x=0.1. In the paramagnetic range, the negative magnetoresistance and the behavior of magnetic moment are a result of orbital glass formation.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shaikhutdinov K. A., Popkov S. I., Semenov S. V., Balaev D. A., Dubrovskiy A. A., Sablina K. A., Volkov N. V.
Заглавие : Low-temperature resistivity of polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in a magnetic fields
Место публикации : J. Phys. Conf. Ser. - 2010. - Vol. 200, Is. SECTION 5. - ISSN 17426588 (ISSN) , DOI 10.1088/1742-6596/200/5/052025
Ключевые слова (''Своб.индексиров.''): antiferromagnetic grains--comparative analysis--ferromagnetic grain--low temperatures--polycrystalline--specific heat measurement--spin dependent tunneling--transport and magnetic properties--antiferromagnetism--electric resistance--europium--grain boundaries--grain size and shape--lanthanum compounds--lead--magnetic field effects--magnetic properties--magnetoresistance--manganese oxide--single crystals--thermal variables measurement--lanthanum
Аннотация: The effect of grain boundaries on magnetoresistance (MR) of manganites have been investigated by the comparative analysis of the properties of single-crystal and polycrystalline (La0.5Eu0.5) 0.7Pb0.3MnO3. While MR of the single crystal is maximum near the Curie temperature and vanishes in the low-temperature region, the polycrystalline (La0.5Eu0.5)0.7Pb 0.3MnO3 sample exhibits high MR in the low-temperature region. In order to clarify the origin of the low-temperature MR, the transport and magnetic properties of the polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in magnetic fields have been supplemented by study of magnetic properties and specific heat measurements. The results obtained could be attributed to spin-dependent tunneling between ferromagnetic grains through insulating antiferromagnetic grain boundaries. © 2010 IOP Publishing Ltd.
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18.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Maksimov D. N., Chesnokov I. Yu., Makarov D. V., Kolovsky A. R.
Заглавие : Landau-zener tunneling in 2d periodic structures in the presense of a gauge field
Коллективы : Euro-Asian Symposium "Trends in MAGnetism": Nanomagnetism
Место публикации : V Euro-Asian simposium "Trend in MAGnetism": Nanomagnetism: abstracts. - Vladivostok: FEFU, 2013. - С. 71. - ISBN 978-5-7444-3124-2
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bulgakov E. N., Kolovsky A. R.
Заглавие : Induced tunneling and localization for a quantum particle in tilted two-dimensional lattices
Коллективы : Russian Academy of Sciences through the SB RAS [29]
Место публикации : Phys. Rev. B: American Physical Society, 2014. - Vol. 89, Is. 3. - Ст.035116. - ISSN 1098-0121, DOI 10.1103/PhysRevB.89.035116. - ISSN 1550-235X
Примечания : Cited References: 17. - The authors express their gratitude to D. N. Maksimov for useful remarks and acknowledge financial support of the Russian Academy of Sciences through the SB RAS integration project No. 29 Dynamics of atomic Bose-Einstein condensates in optical lattices.
Предметные рубрики: DYNAMIC LOCALIZATION
CHARGED-PARTICLE
OPTICAL LATTICE
ELECTRIC-FIELD
DIRAC POINTS
Аннотация: We consider a quantum particle in tilted two-dimensional lattices in the tight-binding approximations. We show that for certain lattice geometries the particle can freely move across the lattice in the direction perpendicular to the vector of the static force. This effect is argued to be analog of the photon-induced tunneling in driven one-dimensional lattices. We calculate the particle dispersion relation by using a method based on the Bogoliubov-Mitropolskii averaging technique from the theory of dynamical systems. This dispersion relation draws the analogy with driven one-dimensional lattices further by eventually showing band collapses when a control parameter is varied.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Nesterov A. I., Ovchinnikov S. G.
Заглавие : Geometric phases and quantum phase transitions in open systems
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2008. - Vol. 78, Is. 1. - Ст.15202. - ISSN 1539-3755, DOI 10.1103/PhysRevE.78.015202
Примечания : Cited References: 29
Предметные рубрики: POINTS
DEGENERACIES
Ключевые слова (''Своб.индексиров.''): chlorine compounds--electron tunneling--ferromagnetism--ising model--magnetic fields--magnetism--open systems--quantum electronics--quantum optics--sedimentation--effective hamiltonian--eigenvalues--first orders--geometric phase--geometric phases--ground-state--hermitian--one-dimensional--open quantum systems--quantum phase transition--quantum phase transitions--transverse-magnetic fields--phase transitions
Аннотация: The relationship is established between quantum phase transitions and complex geometric phases for open quantum systems governed by a non-Hermitian effective Hamiltonian with accidental crossing of the eigenvalues. In particular, the geometric phase associated with the ground state of the one-dimensional dissipative Ising model in a transverse magnetic field is evaluated, and it is demonstrated that the related quantum phase transition is of the first order.
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