| 1. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Hot electrons in magnetic point contacts as a photon source
- 2011
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- We propose to use a point contact between a ferromagnetic and a normal metal in the presence of a magnetic field for creating a large inverted spin population of hot electrons in the contact core. The key point of the proposal is that when these hot electrons relax by flipping their spin, microwave photons are emitted, with a frequency tunable by the applied magnetic field. While point contacts are an established technology, their use as a photon source is a new and potentially very useful application. We show that this photon emission process can be detected by means of transport spectroscopy and demonstrate stimulated emission of radiation in the 10–100 GHz range for a model point contact system using a minority-spin ferromagnetic injector. These results can potentially lead to new types of lasers based on spin injection in metals.
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| 2. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Coulomb promotion of spin-dependent tunneling
- 2005
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 95:11
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Tidskriftsartikel (refereegranskat)abstract
- We study transport of spin-polarized electrons through a magnetic single-electron transistor (SET) in the presence of an external magnetic field. Assuming the SET to have a nanometer size central island with a single-electron level we find that the interplay on the island between coherent spin-flip dynamics and Coulomb interactions can make the Coulomb correlations promote rather than suppress the current through the device. We find the criteria for this new phenomenon-Coulomb promotion of spin-dependent tunneling-to occur. © 2005 The American Physical Society.
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| 3. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Giant shot noise due to mechanical transportation of spin-polarized electrons
- 2008
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Ingår i: Physical Review B. - 1098-0121. ; 77:17, s. 174304-
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Tidskriftsartikel (refereegranskat)abstract
- We show that single-electron "shuttling" of electrons in a magnetic nanoelectromechanical single-electron transistor device can be an efficient tool for studying electron spin-flip relaxation on quantum dots. The reason is traced to a spin blockade of the mechanically aided shuttle current that occurs in devices with highly polarized and collinearly magnetized leads. This results in giant peaks in the shot-noise spectral function, wherein the peak heights are only limited by the rate of electronic spin flips. Therefore, we show that nanomechanical spectroscopy of the spin-flip rate is possible, allowing spin-flip relaxation times as long as 10 mu s to be detected.
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| 4. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Giant super poissonian shot noise in spin-polarized SET structures
- 2007
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Ingår i: Low Temperature Physics. ; 33:9, s. 757-761
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Tidskriftsartikel (refereegranskat)abstract
- We study transport of spin-polarized electrons through a magnetic single-electron transistor (SET) in the presence of an external magnetic field. Assuming the SET to have a nanometer-sized central island with a single electron level, we find that the zero-frequency shot noise diverges as the on-dot spin-flip rate goes to zero, provided the source and drain leads are completely polarized in the same direction. We present an analytical expression for the low-frequency super-Poissonian shot noise that allows one to specify the necessary conditions for the experimental observation of the phenomenon. (c) 2007 American Institute of Physics.
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| 5. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Mechanically assisted spin-dependent transport of electrons
- 2005
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 0163-1829. ; 71:3, s. 35327-1
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Tidskriftsartikel (refereegranskat)abstract
- Spin-dependent tunneling of electrons through magnetic nanostructures containing a mechanically movable quantum dot is considered. It is shown that the mechanically assisted current can be made strongly sensitive to an external magnetic field, leading to a giant magnetotransmittance effect for weak external fields of order 1-10 Oe
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| 6. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Shot noise spectroscopy of electronic spin flips in quantum dots
- 2007
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 90:19
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Tidskriftsartikel (refereegranskat)abstract
- Spin decoherence and spin flips crucially affect the tunneling transport of spin-polarized electrons through a quantum dot connected to magnetic leads. Here, the authors show that the low-frequency shot noise in such structures diverges as the spin relaxation rate for electrons on the dot goes to zero, reaching giant super-Poissonian values for realistic spin-flip rates. It is also shown that combined measurements of the average current and the shot noise as a function of bias voltage and external magnetic field offer a spectroscopic tool for studying electronic spin relaxation rates in this system.
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| 7. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Spin-dependent transport of electrons in a shuttle structure
- 2006
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Ingår i: Theory of Quantum Transport in Metallic and Hybrid Nanostructures. - Dordrecht : Kluwer Academic Publishers. - 1568-2609. - 9781402047770 ; , s. 307-319
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Konferensbidrag (refereegranskat)
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| 8. |
- Ilinskaya, O. A., et al.
(författare)
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Shuttling of spin polarized electrons in molecular transistors
- 2016
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Ingår i: Synthetic Metals. - : Elsevier BV. - 0379-6779. ; 216, s. 83-87
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Tidskriftsartikel (refereegranskat)abstract
- Shuttling of electrons in single-molecule transistors with magnetic leads in the presence of an external magnetic field is considered theoretically. For a current of partially spin-polarized electrons a shuttle instability is predicted to occur for a finite interval of external magnetic field strengths. The lower critical magnetic field is determined by the degree of spin polarization and it vanishes as the spin polarization approaches 100%. The feasibility of detecting magnetic shuttling in a C-60-based molecular transistor with magnetic (Ni) electrodes is discussed (Pasupathy et al. (2004) [7]). (C) 2015 Elsevier B.V. All rights reserved.
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| 9. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Giant lasing effect in magnetic point contacts and its detection by DC electrical measurements
- 2011
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Ingår i: Proc. of SPIE. - 0277-786X. - 9780819484703 ; 7933
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Konferensbidrag (refereegranskat)abstract
- We propose a new principle for a compact solid-state laser in 1-100 THz regime based on a new mechanism for creating spin-flip processes in ferromagnetic conductors. On the base of this mechanism, a giant lasing effect is predicted. The optical gain is estimated to exceed the optical gain of conventional semiconductor lasers by 4 or 5 orders of magnitude. We propose to use a point contact between ferromagnetic metals in order to create an inverted spin-population of hot electrons in the contact region. While point contact spectroscopy is an established technology the use of magnetic point contacts as a photon source is a new and potentially very useful application. We show that the generated photons conveniently can be detected by measuring the current through the illuminated point contact.
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| 10. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Joule heating and current-induced instabilities in magnetic nanocontacts
- 2006
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Ingår i: Physical Review B. - 1098-0121 .- 1550-235X. ; 74:19
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Tidskriftsartikel (refereegranskat)abstract
- We consider the electrical current through a magnetic point contact in the limit of a strong inelastic scattering of electrons. In this limit local Joule heating of the contact region plays a decisive role in determining the transport properties of the point contact. We show that if an applied constant bias voltage exceeds a critical value, the stationary state of the system is unstable, and that periodic, nonharmonic oscillations in time of both the electrical current through the contact and the local temperature in the contact region develop spontaneously. Our estimations show that the necessary experimental conditions for observing such oscillations with characteristic frequencies in the range 10(8)-10(9) Hz can easily be met. We also show a possibility to manipulate upon the magnetization direction of a magnetic grain coupled through a point contact to a bulk ferromagnet by exciting the above-mentioned thermal-electric oscillations.
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| 11. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Microwave-induced spin-flip scattering of electrons in point contacts
- 2011
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Ingår i: Low Temperature Physics. - 1063-777X. ; 37:11, s. 925-932
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Tidskriftsartikel (refereegranskat)abstract
- We investigate resonant interaction of conduction electrons with an electromagnetic field that irradiates a point contact between a ferromagnetic and a normal metal in the presence of a strong magnetic field of order 1 T. We show that electron spin-flips caused by resonant absorption and stimulated emission of photons result in a sharp peak in the magnetic-field dependence of the point-contact resistance. The height of the peak is shown to be directly proportional to the net rate of energy transfer to the electromagnetic field in the point contact due to absorption and stimulated emission of photons. Estimations indicate that our theory can serve as a basis for the explanation of recent experiments [A.M. Kadigrobov et al., New J. Phys. 13, 023007 (2011)].
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| 12. |
- Krive, Ilya V., et al.
(författare)
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Charge and spin effects in mesoscopic Josephson junctions
- 2004
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Ingår i: Fizika Nizkikh Temperatur (Kharkov). - 0132-6414. ; 30, s. 554-
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Tidskriftsartikel (refereegranskat)abstract
- We consider the charge and spin effects in low dimensional superconducting weak, links. The first part of the review deals with the effects of electron - electron interaction in Superconductor/Luttlnger liquid/Superconductor junctions. The experimental realization of this mesoscopic hybrid system can be the individual single wall carbon nanotube that bridges the gap between two bulk superconductors. The dc Josephson current through a Luttinger liquid is evaluated in the limits of perfectly and poorly transmitting junctions. The relationship between the Josephson effect in a long SNS junction and the Casimir effect is discussed. In the second part of the paper we review the recent results concerning the influence of the Zeeman and Rashba interactions on the thermodynamical properties of ballistic S-QW-S junction fabricated in two dimensional electron gas. It is shown that in magnetically controlled junction there are conditions for resonant Cooper pair transition which results in giant supercurrent through a tunnel junction and a giant magnetic response of a multichannel SNS junction. The supercurrent induced by the joint action of the Zeeman and Rashba interactions in 1D quantum wires connected to bulk superconductors is predicted.
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| 13. |
- Kulinich, Sergeij I., et al.
(författare)
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Nanomechanics of a magnetic shuttle device
- 2014
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Ingår i: Low temperature physics. - : AIP Publishing. - 1063-777X .- 1090-6517. ; 40:10, s. 1161-1169
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Tidskriftsartikel (refereegranskat)abstract
- We show that self sustained mechanical vibrations in a model magnetic shuttle device can be driven by both the charge and the spin accumulated on the movable central island of the device. Different scenarios for how spin- and charge-induced shuttle instabilities may develop are discussed and shown to depend on whether there is a Coulomb blockade of tunneling or not. The crucial role of electronic spin flips in a magnetically driven shuttle is established and shown to cause giant magnetoresistance and dynamic magnetostriction effects.
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| 14. |
- Kulinich, Sergeij I., et al.
(författare)
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Single-Electron Shuttle Based on Electron Spin
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:11
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Tidskriftsartikel (refereegranskat)abstract
- A nanoelectromechanical device based on magnetic exchange forces and electron spin flips induced by a weak external magnetic field is suggested. It is shown that this device can operate as a new type of single-electron "shuttle" in the Coulomb blockade regime of electron transport.
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| 15. |
- Kulinich, Sergeij I., et al.
(författare)
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Umklapp-assisted electron transport oscillations in metal superlattices
- 2012
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Ingår i: Physical Review B. - 1098-0121. ; 85:18, s. artikel nr 184202-
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Tidskriftsartikel (refereegranskat)abstract
- We consider a superlattice of parallel metal tunnel junctions with a spatially nonhomogeneous probability for electrons to tunnel. In such structures tunneling can be accompanied by electron scattering that conserves energy but not momentum. In the special case of a tunneling probability that varies periodically with period a in the longitudinal direction, i.e., perpendicular to the junctions, electron tunneling is accompanied by umklapp scattering, where the longitudinal momentum changes by a multiple of h/a. We predict that as a result a sequence of metal-insulator transitions can be induced by an external electric or magnetic field as the field strength is increased.
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| 16. |
- Shekhter, Robert I., 1947, et al.
(författare)
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Electronic spin working mechanically (Review Article)
- 2014
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Ingår i: Low temperature physics. - : AIP Publishing. - 1063-777X .- 1090-6517. ; 40:7, s. 600-614
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Tidskriftsartikel (refereegranskat)abstract
- A single-electron tunneling (SET) device with a nanoscale central island that can move with respect to the bulk source- and drain electrodes allows for a nanoelectromechanical (NEM) coupling between the electrical current through the device and mechanical vibrations of the island. Although an electromechanical “shuttle” instability and the associated phenomenon of single-electron shuttling were predicted more than 15 years ago, both theoretical and experimental studies of NEM-SET structures are still carried out. New functionalities based on quantum coherence, Coulomb correlations and coherent electron-spin dynamics are of particular current interest. In this article we present a short review of recent activities in this area.
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| 17. |
- Skorobagatko, G. A., et al.
(författare)
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Magnetopolaronic effects in electron transport through a single-level vibrating quantum dot
- 2011
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Ingår i: Low Temperature Physics. - 1063-777X. ; 37:12, s. 1032-1037
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Tidskriftsartikel (refereegranskat)abstract
- Magnetopolaronic effects are considered in electron transport through a single-level vibrating quantum dot subjected to a transverse (to the current flow) magnetic field. It is shown that the effects are most pronounced in the regime of sequential electron tunneling, where a polaronic blockade of the current at low temperatures and an anomalous temperature dependence of the magnetoconductance are predicted. In contrast, for resonant tunneling of polarons the peak conductance is not affected by the magnetic field.
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| 18. |
- Sonne, Gustav, 1982, et al.
(författare)
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Superconducting pumping of nanomechanical vibrations
- 2008
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Ingår i: Physical Review B. - 1098-0121. ; 78, s. 144501-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that a supercurrent can pump energy from a battery that provides a voltage bias into nanomechanical vibrations. Using a device containing a nanowire Josephson weak link as an example we show that a nonlinear coupling between the supercurrent and a static external magnetic field leads to a Lorentz force that excites bending vibrations of the wire at resonance conditions. We also demonstrate the possibility to achieve more than one regime of stationary nonlinear vibrations and how to detect them via the associated dc Josephson currents and we discuss possible applications of such a multistable nanoelectromechanical dynamics.
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| 19. |
- Vikström, Anton, 1986, et al.
(författare)
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Nanoelectromechanical Heat Engine Based on Electron-Electron Interaction
- 2016
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 117:24
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically show that a nanoelectromechanical system can be mechanically actuated by a heat flow through it via an electron-electron interaction. In contrast to most known actuation mechanisms in similar systems, this new mechanism does not involve an electronic current nor external ac fields. Instead, the mechanism relies on deflection-dependent tunneling rates and a heat flow which is mediated by an electron-electron interaction while an electronic current through the device is prohibited by, for instance, a spin-valve effect. Therefore, the system resembles a nanoelectromechanical heat engine. We derive a criterion for the mechanical instability and estimate the amplitude of the resulting self-sustained oscillations. Estimations show that the suggested phenomenon can be studied using available experimental techniques.
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