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Author Moura, V.N.; Dantas, D.S.; Farias, G.A.; Chaves, A.; Milošević, M.V.
Title Latent superconductivity at parallel interfaces in a superlattice dominated by another collective quantum phase Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 1 Pages 014516-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We theoretically examine behavior of superconductivity at parallel interfaces separating the domains of another dominant collective excitation, such as charge density waves or spin density waves. Due to their competitive coupling in a two-component Ginzburg-Landau model, suppression of the dominant order parameter at the interfacial planes allows for nucleation of the (hidden) superconducting order parameter at those planes. In such a case, we demonstrate how the number of the parallel interfacial planes and the distance between them are linked to the number and the size of the emerging superconducting gaps in the system, as well as the versatility and temperature evolution of the possible superconducting phases. These findings bear relevance to a broad selection of known layered superconducting materials, as well as to further design of artificial (e.g., oxide) superlattices, where the interplay between competing order parameters paves the way towards otherwise unattainable superconducting states, some with enhanced superconducting critical temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000834346000004 Publication Date 2022-07-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:189520 Serial 7179
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Author Vizarim, N.P.; Souza, J.C.B.; Reichhardt, C.J.O.; Reichhardt, C.; Milošević, M.V.; Venegas, P.A.
Title Soliton motion in skyrmion chains : stabilization and guidance by nanoengineered pinning Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 22 Pages 224409-224412
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using a particle-based model we examine the depinning motion of solitons in skyrmion chains in quasi -onedimensional (1D) and two-dimensional (2D) systems containing embedded 1D interfaces. The solitons take the form of a particle or hole in a commensurate chain of skyrmions. Under an applied drive, just above a critical depinning threshold, the soliton moves with a skyrmion Hall angle of zero. For higher drives, the entire chain depins, and in a 2D system we observe that both the solitons and chain move at zero skyrmion Hall angle and then transition to a finite skyrmion Hall angle as the drive increases. In a 2D system with a 1D interface that is at an angle to the driving direction, there can be a reversal of the sign of the skyrmion Hall angle from positive to negative. Our results suggest that solitons in skyrmion systems could be used as information carriers in racetrack geometries that would avoid the drawbacks of finite skyrmion Hall angles. The soliton states become mobile at significantly lower drives than the depinning transition of the skyrmion chains themselves.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000823038900004 Publication Date 2022-06-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 2 Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:189671 Serial 7209
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Author Cunha, S.M.; da Costa, D.R.; Pereira, J.M., Jr.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M.
Title Tunneling properties in α-T₃ lattices : effects of symmetry-breaking terms Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 16 Pages 165402-165414
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The alpha-T3 lattice model interpolates a honeycomb (graphene-like) lattice and a T3 (also known as dice) lattice via the parameter alpha. These lattices are made up of three atoms per unit cell. This gives rise to an additional dispersionless flat band touching the conduction and valence bands. Electrons in this model are analogous to Dirac fermions with an enlarged pseudospin, which provides unusual tunneling features like omnidirectional Klein tunneling, also called super-Klein tunneling (SKT). However, it is unknown how small deviations in the equivalence between the atomic sites, i.e., variations in the alpha parameter, and the number of tunnel barriers changes the transmission properties. Moreover, it is interesting to learn how tunneling occurs through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. In this paper we investigate these properties, its dependence on the number of square barriers and the alpha parameter for either gapped and gapless cases. Furthermore, we compare these results to the case where electrons tunnel from a region with linear dispersion to a region with a bandgap. In the latter case, contrary to tunneling through a potential barrier, the SKT is no longer observed. Finally, we find specific cases where transmission is allowed due to a symmetry breaking of sublattice equivalence.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000805195200001 Publication Date 2022-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:188614 Serial 7222
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Author Gurel, T.; Altunay, Y.A.; Bulut, P.; Yildirim, S.; Sevik, C.
Title Comprehensive investigation of the extremely low lattice thermal conductivity and thermoelectric properties of BaIn₂Te₄ Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 19 Pages 195204-195210
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Recently, an extremely low lattice thermal conductivity value has been reported for the alkali-based telluride material BaIn2Te4. The value is comparable with low-thermal conductivity metal chalcogenides, and the glass limit is highly intriguing. Therefore, to shed light on this issue, we performed first-principles phonon thermal transport calculations. We predicted highly anisotropic lattice thermal conductivity along different directions via the solution of the linearized phonon Boltzmann transport equation. More importantly, we determined several different factors as the main sources of the predicted ultralow lattice thermal conductivity of this crystal, such as the strong interactions between low-frequency optical phonons and acoustic phonons, small phonon group velocities, and lattice anharmonicity indicated by large negative mode Gruneisen parameters. Along with thermal transport calculations, we also investigated the electronic transport properties by accurately calculating the scattering mechanisms, namely the acoustic deformation potential, ionized impurity, and polar optical scatterings. The inclusion of spin-orbit coupling (SOC) for electronic structure is found to strongly affect the p-type Seebeck coefficients. Finally, we calculated the thermoelectric properties accurately, and the optimal ZT value of p-type doping, which originated from high Seebeck coefficients, was predicted to exceed unity after 700 K and have a direction averaged value of 1.63 (1.76 in the y-direction) at 1000 K around 2 x 1020 cm-3 hole concentration. For n-type doping, a ZT around 3.2 x 1019 cm-3 concentration was predicted to be a direction-averaged value of 1.40 (1.76 in the z-direction) at 1000 K, mostly originating from its high electron mobility. With the experimental evidence of high thermal stability, we showed that the BaIn2Te4 compound has the potential to be a promising mid- to high-temperature thermoelectric material for both p-type and n-type systems with appropriate doping.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000918954800001 Publication Date 2022-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:194384 Serial 7290
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Author Lazarevic, N.; Baum, A.; Milosavljevic, A.; Peis, L.; Stumberger, R.; Bekaert, J.; Solajic, A.; Pesic, J.; Wang, A.; Scepanovic, M.; Abeykoon, A.M.M.; Milošević, M.V.; Petrovic, C.; Popovic, Z.V.; Hackl, R.
Title Evolution of lattice, spin, and charge properties across the phase diagram of Fe1-xSx Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 9 Pages 094510-94519
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A Raman scattering study covering the entire substitution range of the FeSe1-xSx solid solution is presented. Data were taken as a function of sulfur concentration x for 0 <= x <= 1, of temperature and of scattering symmetry. All types of excitations including phonons, spins, and charges are analyzed in detail. It is observed that the energy and width of the iron-related B-1g phonon mode vary continuously across the entire range of sulfur substitution. The A(1g) chalcogenide mode disappears above x = 0.23 and reappears at a much higher energy for x = 0.69. In a similar way the spectral features appearing at finite doping in A(1g) symmetry vary discontinuously. The magnetic excitation centered at approximately 500 cm(-1) disappears above x = 0.23 where the A(1g) lattice excitations exhibit a discontinuous change in energy. The low-energy mode associated with fluctuations displays maximal intensity at the nematostructural transition and thus tracks the phase boundary.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000917933500004 Publication Date 2022-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:194397 Serial 7304
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Author Pascucci, F.; Conti, S.; Neilson, D.; Tempère, J.; Perali, A.
Title Josephson effect as a signature of electron-hole superfluidity in bilayers of van der Waals heterostructures Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 22 Pages L220503-6
Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
Abstract We investigate a Josephson junction in an electron-hole superfluid in a double-layer transition metal dichalco-genide heterostructure. The observation of a critical tunneling current is a clear signature of superfluidity. In addition, we find the BCS-BEC crossover physics in the narrow barrier region controls the critical current across the entire system. The corresponding critical velocity, which is measurable in this system, has a maximum when the excitations pass from bosonic to fermionic. Remarkably, this occurs for the density at the boundary of the BEC to BCS-BEC crossover regime determined from the condensate fraction. This provides, in a semiconductor system, an experimental way to determine the position of this boundary.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000903924400007 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:193402 Serial 7316
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Author Nulens, L.; Dausy, H.; Wyszynski, M.J.; Raes, B.; Van Bael, M.J.; Milošević, M.V.; Van de Vondel, J.
Title Metastable states and hidden phase slips in nanobridge SQUIDs Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 13 Pages 134518-134519
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We fabricated an asymmetric nanoscale SQUID consisting of one nanobridge weak link and one Dayem bridge weak link. The current phase relation of these particular weak links is characterized by multivaluedness and linearity. While the latter is responsible for a particular magnetic field dependence of the critical current (so-called vorticity diamonds), the former enables the possibility of different vorticity states (phase winding numbers) existing at one magnetic field value. In experiments the observed critical current value is stochastic in nature, does not necessarily coincide with the current associated with the lowest energy state and critically depends on the measurement conditions. In this paper, we unravel the origin of the observed metastability as a result of the phase dynamics happening during the freezing process and while sweeping the current. Moreover, we employ special measurement protocols to prepare the desired vorticity state and identify the (hidden) phase slip dynamics ruling the detected state of these nanodevices. In order to gain insights into the dynamics of the condensate and, more specifically the hidden phase slips, we performed time-dependent Ginzburg-Landau simulations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000904657300007 Publication Date 2022-10-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 1 Open Access OpenAccess
Notes Approved (down) Most recent IF: 3.7
Call Number UA @ admin @ c:irua:193393 Serial 7321
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