| 1. |
- Lukyanchuk, I., et al.
(author)
-
Rayleigh instability of confined vortex droplets in critical superconductors
- 2015
-
In: Nature Physics. - 1745-2473 .- 1745-2481. ; 11:1, s. 21-25
-
Journal article (peer-reviewed)abstract
- Depending on the Ginzburg-Landau parameter kappa, superconductors can either be fully diamagnetic if kappa < 1/root 2 (type I superconductors) or allow magnetic flux to penetrate through Abrikosov vortices if kappa > 1/root 2 (type II superconductors; refs 1,2). At the Bogomolny critical point, kappa = kappa(c) = 1/root 2, a state that is infinitely degenerate with respect to vortex spatial configurations arises(3,4). Despite in-depth investigations of conventional type I and type II superconductors, a thorough understanding of the magnetic behaviour in the near-Bogomolny critical regime at kappa similar to kappa(c) remains lacking. Here we report that in confined systems the critical regime expands over a finite interval of kappa forming a critical superconducting state. We show that in this state, in a sample with dimensions comparable to the vortex core size, vortices merge into a multi-quanta droplet, which undergoes Rayleigh instability(5) on increasing kappa and decays by emitting single vortices. Superconducting vortices realize Nielsen-Olesen singular solutions of the Abelian Higgs model, which is pervasive in phenomena ranging from quantum electrodynamics to cosmology(6-9). Our study of the transient dynamics of Abrikosov-Nielsen-Olesen vortices in systems with boundaries promises access to non-trivial effects in quantum field theory by means of bench-top laboratory experiments.
|
|
| 2. |
|
|
| 3. |
- Shekhter, Robert I., 1947, et al.
(author)
-
Nanomechanical shuttle transfer of electrons
- 2007
-
In: Journal of Computational and Theoretical Nanoscience. ; 4, s. 860-895
-
Journal article (peer-reviewed)abstract
- Small metal particles embedded in a material subject to an external electric field can contribute to the conductance by mechanically transporting charge. This was already demonstrated in Millikan's pioneering experiment that proved that charge is quantized. While the effect of charge quantization can be pronounced for submicron conducting particles and lead to Coulomb blockade of W tunnelling, the nanomechanical aspect of single-electron tunnelling becomes prominent only in 5 nanometer-size self-assembled structures. The coupling between mechanical deformations and LU electronic charge transport in composite materials with nanoscale components gives rise to a new class of phenomena-nanoelectromechanical transport-and opens up a new route in nanotechnology. The interplay between the electronic and mechanical degrees of freedom is especially important in nanocomposites consisting of materials with very different elastic properties. A typical system of this kind is a single-electron transistor (SET) with cleformable tunnel barriers, a so called Nano-Electro-Mechanic.al SET (NEM-SET). The new kind of electron transport in this and other types of nanodevices is referred to as "shuttle transport" of electrons, which implies that electrons is transferred between metallic leads via a movable small-sized cluster. The present review is devoted to the fundamental aspects of shuttle transport and to a description of major developments in the theoretical and experimental research in the field. Prospective applications of this exciting phenomenon that remarkably combines traditional mechanics of materials with the most advanced effects of quantum physics, will also be touched upon.
|
|
| 4. |
- Shekhter, Robert I., 1947, et al.
(author)
-
Shuttle transport in nanostructures
- 2006
-
In: Handbook of theoretical and computational nanotechnology. - : American Scientific Publishers. - 1588830470
-
Book chapter (other academic/artistic)abstract
- The coupling between mechanical deformations and electronic charge transport in nanostructures and in composite materials with nanoscale components gives rise to a new class of phenomena | nanoelectromechanical transport | and opens up a new route in nanotechnology. The interplay between the electronic and mechanical degrees of freedom is especially important in nanocomposites consisting of materials with very di®erent elastic properties. Mechanical degrees of freedom take on a primary role in the charge transfer process in many single-electron devices, where transport is controlled by quantum-mechanical tunnelling and Coulomb interactions, but where tunnel barriers can be modi¯ed as a result of mechanical motion. A typical system of this kind is a single-electron transistor (SET) with deformable tunnel barriers, a so called Nano-Electro-Mechanical SET (NEM- SET). The new kind of electron transport in this and other types of nanodevices is referred to as "shuttle transport" of electrons, which implies that electrons is transferred between metallic leads via a movable small-sized cluster. The present review is devoted to the fundamental aspects of shuttle transport and to a description of major developments in the theoretical and experimental research in the ¯eld. Prospective applications of this exciting phenomenon that remarkably combines traditional mechanics of materials with the most advanced e®ects of quantum physics, will also be touched upon.
|
|
| 5. |
|
|
| 6. |
- Gorelik, Leonid, 1952, et al.
(author)
-
Coulomb promotion of spin-dependent tunneling
- 2005
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 95:11
-
Journal article (peer-reviewed)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.
|
|
| 7. |
- Gorelik, Leonid, 1952, et al.
(author)
-
Giant shot noise due to mechanical transportation of spin-polarized electrons
- 2008
-
In: Physical Review B. - 1098-0121. ; 77:17, s. 174304-
-
Journal article (peer-reviewed)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.
|
|
| 8. |
- Gorelik, Leonid, 1952, et al.
(author)
-
Giant super poissonian shot noise in spin-polarized SET structures
- 2007
-
In: Low Temperature Physics. ; 33:9, s. 757-761
-
Journal article (peer-reviewed)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.
|
|
| 9. |
- Gorelik, Leonid, 1952, et al.
(author)
-
Mechanically assisted spin-dependent transport of electrons
- 2005
-
In: Physical Review B (Condensed Matter and Materials Physics). - 0163-1829. ; 71:3, s. 35327-1
-
Journal article (peer-reviewed)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
|
|
| 10. |
- Gorelik, Leonid, 1952, et al.
(author)
-
Shot noise spectroscopy of electronic spin flips in quantum dots
- 2007
-
In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 90:19
-
Journal article (peer-reviewed)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.
|
|
| 11. |
|
|
