“Optimizing mesoscopic two-band superconductors for observation of fractional vortex states”. Piña JC, de Souza Silva CC, Milošević, MV, Physica: C : superconductivity 503, 48 (2014). http://doi.org/10.1016/j.physc.2014.04.017
Abstract: Using the two-component Ginzburg-Landau model, we investigate the effect of sample size and magnitude and homogeneity of external magnetic field on the stability of fractional vortex states in a mesoscopic two-band superconducting disk. We found that each fractional state has a preferable sample size, for which the range of applied field in which the state is stable is pronouncedly large. Vice versa, there exists an optimal magnitude of applied field for which a large range of possible sample radii will support the considered fractional state. Finally, we show that the stability of fractional states can be enhanced even further by magnetic nanostructuring of the sample, i.e. by suitably chosen geometrical parameters and magnetic moment of a ferromagnetic dot placed on top of the superconducting disk. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 5
DOI: 10.1016/j.physc.2014.04.017
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“The superconducting state in square mesoscopic samples with two and four antidots”. Berdiyorov GR, Baelus BJ, Milošević, MV, Peeters FM, Physica: C : superconductivity 404, 56 (2004). http://doi.org/10.1016/j.physc.2003.09.111
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 3
DOI: 10.1016/j.physc.2003.09.111
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“The Ginzburg-Landau theory in application”. Milošević, MV, Geurts R, Physica: C : superconductivity 470, 791 (2010). http://doi.org/10.1016/j.physc.2010.02.056
Abstract: A numerical approach to GinzburgLandau (GL) theory is demonstrated and we review its applications to several examples of current interest in the research on superconductivity. This analysis also shows the applicability of the two-dimensional approach to thin superconductors and the re-defined effective GL parameter κ. For two-gap superconductors, the conveniently written GL equations directly show that the magnetic behavior of the sample depends not just on the GL parameter of two bands, but also on the ratio of respective coherence lengths.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 66
DOI: 10.1016/j.physc.2010.02.056
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“The healing lengths in two-band superconductors in extended Ginzburg-Landau theory”. Komendová, L, Shanenko AA, Milošević, MV, Peeters FM, Physica: C : superconductivity 479, 126 (2012). http://doi.org/10.1016/j.physc.2011.12.017
Abstract: We study the vortex profiles in two-gap superconductors using the extended Ginzburg-Landau theory. The results shed more light on the disparity between the effective length scales in two bands. We compare the behavior expected from the standard Ginzburg-Landau theory with this new approach, and find good qualitative agreement in the case of LiFeAs. (C) 2011 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 1
DOI: 10.1016/j.physc.2011.12.017
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“Triplet vortex state in magnetic superconductors: effects of boundaries”. Doria MM, Romaguera AR de C, Milošević, MV, Peeters FM, Physica: C : superconductivity 468, 572 (2008). http://doi.org/10.1016/j.physc.2007.11.078
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 1
DOI: 10.1016/j.physc.2007.11.078
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“Vortex-antivortex molecules induced by a magnetic disk on top of a superconducting film: influence of the magnet geometry”. Milošević, MV, Peeters FM, Physica: C : superconductivity 404, 281 (2004). http://doi.org/10.1016/j.physc.2003.11.039
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 4
DOI: 10.1016/j.physc.2003.11.039
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“Vortex-antivortex nucleation in superconducting films with arrays of in-plane dipoles”. Milošević, MV, Peeters FM, Physica: C : superconductivity 437/438, 208 (2006). http://doi.org/10.1016/j.physc.2005.12.078
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 16
DOI: 10.1016/j.physc.2005.12.078
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“Vortex lattice in effective type-I superconducting films with periodic arrays of submicron holes”. Berdiyorov GR, Milošević, MV, Peeters FM, Physica: C : superconductivity 437/438, 25 (2006). http://doi.org/10.1016/j.physc.2005.12.032
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 8
DOI: 10.1016/j.physc.2005.12.032
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“Dynamics of skyrmions and edge states in the resistive regime of mesoscopic p-wave superconductors”. Fernández Becerra V, Milošević, MV, Physica: C : superconductivity 533, 91 (2017). http://doi.org/10.1016/J.PHYSC.2016.07.002
Abstract: In a mesoscopic sample of a chiral p-wave superconductor, novel states comprising skyrmions and edge states have been stabilized in out-of-plane applied magnetic field. Using the time-dependent Ginzburg-Landau equations we shed light on the dynamic response of such states to an external applied current. Three different regimes are obtained, namely, the superconducting (stationary), resistive (non-stationary) and normal regime, similarly to conventional s-wave superconductors. However, in the resistive regime and depending on the external current, we found that moving skyrmions and the edge state behave distinctly different from the conventional kinematic vortex, thereby providing new fingerprints for identification of p-wave superconductivity. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 3
DOI: 10.1016/J.PHYSC.2016.07.002
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“Stability of CH3 molecules trapped on hydrogenated sites of graphene”. Berdiyorov GR, Milošević, MV, Peeters FM, van Duin AT, Physica: B : condensed matter 455, 60 (2014). http://doi.org/10.1016/j.physb.2014.07.046
Abstract: We study the effect of a hydrogen atom on the thermal stability of a trapped CH3 molecule on graphene using ReaxFF molecular dynamics simulations. Due to the hydrogen-molecule interaction, enhanced pinning of the CH3 molecule is observed when it is positioned adjacent to the graphene site with the hydrogen atom. We discuss the formation process of such a stable configuration, which originates from different adhesion and migration energies of the hydrogen atom and the CH3 molecule. We also studied the effect of the CH3-H configuration on the electronic transport properties of graphene nanoribbons using first principles density-functional calculations. We found that the formation of the CH3-H structure results in extra features in the transmission spectrum due to the formation of strongly localized states, which are absent when the CH3 molecule is trapped on pristine graphene. Our findings will be useful in exploiting gas sensing properties of graphene, especially for selective detection of individual molecules. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.386
Times cited: 5
DOI: 10.1016/j.physb.2014.07.046
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“Magnetic ferroelectric metal in bilayer Fe₃GeTe₂, under interlayer sliding”. Miao X, Milošević, M, Zhang C, Physica: B : condensed matter 694, 416427 (2024). http://doi.org/10.1016/J.PHYSB.2024.416427
Abstract: The inherent interlayer freedom in van der Waals stacked materials provides an excellent opportunity to investigate ferroelectric-like behavior through interlayer translation. Based on first-principles calculations, we find that the interlayer sliding in Fe3GeTe2 (FGT) bilayer enables the coexistence of polarization, metallicity, and ferromagnetism. We find that the polarization is induced by the uncompensated vertical interlayer charge transfer, and can be switched by an in-plane interlayer sliding. A moderate biaxial strain can reverse the polarization direction of the sliding FGT bilayer. The vertical polarization disentangles with the in-plane conductivity as was previously seen in the sliding ferroelectric WTe2 bilayer. Our work proposes an extremely rare magnetic ferroelectric metal phase that is useful for magnetoelectric and spintronic applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.8
DOI: 10.1016/J.PHYSB.2024.416427
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“Vortex states in mescopic superconductors”. Peeters FM, Baelus BJ, Milošević, MV, Physica. E: Low-dimensional systems and nanostructures 18, 312 (2003). http://doi.org/10.1016/S1386-9477(02)01058-5
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 1
DOI: 10.1016/S1386-9477(02)01058-5
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“Wave-packet propagation in a graphene geometric diode”. Andelkovic M, Rakhimov KY, Chaves A, Berdiyorov GR, Milošević, MV, Physica. E: Low-dimensional systems and nanostructures 147, 115607 (2023). http://doi.org/10.1016/J.PHYSE.2022.115607
Abstract: Dynamics of electron wave-packets is studied using the continuum Dirac model in a graphene geometric diode where the propagation of the wave packet is favored in certain direction due to the presence of geometric constraints. Clear rectification is obtained in the THz frequency range with the maximum rectification level of 3.25, which is in good agreement with recent experiments on graphene ballistic diodes. The rectification levels are considerably higher for systems with narrower channels. In this case, the wave packet transmission probabilities and rectification rate also strongly depend on the energy of the incident wave packet, as a result of the quantum nature of energy levels along such channels. These findings can be useful for fundamental understanding of the charge carrier dynamics in graphene geometry diodes.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 3.3
Times cited: 1
DOI: 10.1016/J.PHYSE.2022.115607
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“Ground state configurations of two-dimensional plasma crystals under long-range attractive particle interaction force”. Chen Z, Kong M, Milošević, MV, Wu Y, Physica scripta 67, 439 (2003). http://doi.org/10.1238/Physica.Regular.067a00439
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.28
Times cited: 4
DOI: 10.1238/Physica.Regular.067a00439
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“Spontaneous emergence of Josephson junctions in homogeneous rings of single-crystal Sr₂RuO₄”. Yasui Y, Lahabi K, Fernández Becerra V, Fermin R, Anwar MS, Yonezawa S, Terashima T, Milošević, MV, Aarts J, Maeno Y, npj Quantum Materials 5, 21 (2020). http://doi.org/10.1038/S41535-020-0223-7
Abstract: The chiral p-wave order parameter in Sr2RuO4 would make it a special case amongst the unconventional superconductors. A consequence of this symmetry is the possible existence of superconducting domains of opposite chirality. At the boundary of such domains, the locally suppressed condensate can produce an intrinsic Josephson junction. Here, we provide evidence of such junctions using mesoscopic rings, structured from Sr2RuO4 single crystals. Our order parameter simulations predict such rings to host stable domain walls across their arms. This is verified with transport experiments on loops, with a sharp transition at 1.5 K, which show distinct critical current oscillations with periodicity corresponding to the flux quantum. In contrast, loops with broadened transitions at around 3 K are void of such junctions and show standard Little-Parks oscillations. Our analysis demonstrates the junctions are of intrinsic origin and makes a compelling case for the existence of superconducting domains.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Times cited: 10
DOI: 10.1038/S41535-020-0223-7
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“Composite vortex ordering in superconducting films with arrays of blind holes”. Berdiyorov GR, Milošević, MV, Peeters FM, New journal of physics 11, 013025 (2009). http://doi.org/10.1088/1367-2630/11/1/013025
Abstract: The pinning properties of a superconducting thin film with a square array of blind holes are studied using the nonlinear GinzburgLandau theory. Although blind holes provide a weaker pinning potential than holes (also called antidots), several novel vortex structures are predicted for different size and thickness of the blind holes. Orientational dimer and trimer vortex states as well as concentric vortex shells can nucleate in the blind holes. In addition, we predict the stabilization of giant vortices that may be located both in the pinning centers and/or at the interstitial sites, as well as the combination of giant vortices with sets of individual vortices. For large blind holes, local vortex shell structures inside the blind holes may transfer their symmetry to interstitial vortices as well. The subtle interplay of shell formation and traditional Abrikosov vortex lattices inside the blind holes is also studied for different numbers of trapped vortices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 33
DOI: 10.1088/1367-2630/11/1/013025
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“Influence of artificial pinning on vortex lattice instability in superconducting films”. Silhanek AV, Leo A, Grimaldi G, Berdiyorov GR, Milošević, MV, Nigro A, Pace S, Verellen N, Gillijns W, Metlushko V, Ilić, B, Zhu X, Moshchalkov VV;, New journal of physics 14, 053006 (2012). http://doi.org/10.1088/1367-2630/14/5/053006
Abstract: In superconducting films under an applied dc current, we analyze experimentally and theoretically the influence of engineered pinning on the vortex velocity at which the flux-flow dissipation undergoes an abrupt transition from low to high resistance. We argue, based on a nonuniform distribution of vortex velocity in the sample, that in strongly disordered systems the mean critical vortex velocity for flux-flow instability (i) has a nonmonotonic dependence on magnetic field and (ii) decreases as the pinning strength is increased. These findings challenge the generally accepted microscopic model of Larkin and Ovchinnikov (1979 J. Low. Temp. Phys. 34 409) and all subsequent refinements of this model which ignore the presence of pinning centers.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 40
DOI: 10.1088/1367-2630/14/5/053006
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“Vortex matter in oblate mesoscopic superconductors with a hole: broken symmetry vortex states and multi-vortex entry”. Xu B, Milošević, MV, Peeters FM, New journal of physics 11, 013020 (2009). http://doi.org/10.1088/1367-2630/11/1/013020
Abstract: Using three-dimensional (3D) numerical discretization of the GinzburgLandau (GL) equations, we investigate the superconducting state of a sphere with a piercing hole in the presence of a magnetic field. In the case of samples with central perforation, in axially applied homogeneous magnetic field, we realized unconventional vortex states of broken symmetry due to complex, 3D competing interactions, which depend on the GL parameter ê. For certain sizes of the sample, non-hysteretic multi-vortex entry and exit is predicted with the non-existence of some vorticities as stable states. In a tilted magnetic field, we studied the gradual transformation of 3D flux patterns into 1D vortex chains, where vortices align along the perforation, and the evolvement of the multi-vortex entry as well. We analyze the flux-guiding ability of the hole in a tilted field, which leads to fractional flux response in magnetization M(H) curves.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 8
DOI: 10.1088/1367-2630/11/1/013020
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“Diversified vortex phase diagram for a rotating trapped two-band Fermi gas in the BCS-BEC crossover”. Klimin SN, Tempere J, Milošević, MV, New journal of physics 20, 025010 (2018). http://doi.org/10.1088/1367-2630/AAACEB
Abstract: We report the equilibrium vortex phase diagram of a rotating two-band Fermi gas confined to a cylindrically symmetric parabolic trapping potential, using the recently developed finite-temperature effective field theory (Klimin et al 2016 Phys. Rev. A 94 023620). A non-monotonic resonant dependence of the free energy as a function of the temperature and the rotation frequency is revealed for a two-band superfluid. We particularly focus on novel features that appear as a result of interband interactions and can be experimentally resolved. The resonant dependence of the free energy is directly manifested in vortex phase diagrams, where areas of stability for both integer and fractional vortex states are found. The study embraces the BCS-BEC crossover regime and the entire temperature range below the critical temperature T-c. Significantly different behavior of vortex matter as a function of the interband coupling is revealed in the BCS and BEC regimes.
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 6
DOI: 10.1088/1367-2630/AAACEB
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“Open circuit voltage generated by dragging superconducting vortices with a dynamic pinning potential”. Xue C, He A, Milošević, MV, Silhanek A V, Zhou Y-H, New journal of physics 21, 113044 (2019). http://doi.org/10.1088/1367-2630/AB54AE
Abstract: We theoretically investigate, through Ginzburg?Landau simulations, the possibility to induce an open circuit voltage in absence of applied current, by dragging superconducting vortices with a dynamic pinning array as for instance that created by a nearby sliding vortex lattice or moving laser spots. Different dynamic regimes, such as synchronous vortex motion or dynamic vortex chains consisting of laggard vortices, can be observed by varying the velocity of the sliding pinning potential and the applied magnetic field. Additionally, due to the edge barrier, significantly different induced voltage is found depending on whether the vortices are dragged along the superconducting strip or perpendicular to the lateral edges. The output voltage in the proposed mesoscopic superconducting dynamo can be tuned by varying size, density and directions of the sliding pinning potential.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 6
DOI: 10.1088/1367-2630/AB54AE
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“Rayleigh instability of confined vortex droplets in critical superconductors”. Lukyanchuk I, Vinokur VM, Rydh A, Xie R, Milošević, MV, Welp U, Zach M, Xiao ZL, Crabtree GW, Bending SJ, Peeters FM, Kwok WK, Nature physics 11, 21 (2015). http://doi.org/10.1038/NPHYS3146
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.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 22.806
Times cited: 20
DOI: 10.1038/NPHYS3146
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“Direct observation of Josephson vortex cores”. Roditchev D, Brun C, Serrier-Garcia L, Cuevas JC, Bessa VHL, Milošević, MV, Debontridder F, Stolyarov V, Cren T, Nature physics 11, 332 (2015). http://doi.org/10.1038/nphys3240
Abstract: Superconducting correlations may propagate between two superconductors separated by a tiny insulating or metallic barrier, allowing a dissipationless electric current to flow(1,2). In the presence of a magnetic field, the maximum supercurrent oscillates(3) and each oscillation corresponding to the entry of one Josephson vortex into the barrier(4). Josephson vortices are conceptual blocks of advanced quantum devices such as coherent terahertz generators(5) or qubits for quantum computing(6), in which on-demand generation and control is crucial. Here, we map superconducting correlations inside proximity Josephson junctions(7) using scanning tunnelling microscopy. Unexpectedly, we find that such Josephson vortices have real cores, in which the proximity gap is locally suppressed and the normal state recovered. By following the Josephson vortex formation and evolution we demonstrate that they originate from quantum interference of Andreev quasiparticles(8), and that the phase portraits of the two superconducting quantum condensates at edges of the junction decide their generation, shape, spatial extent and arrangement. Our observation opens a pathway towards the generation and control of Josephson vortices by applying supercurrents through the superconducting leads of the junctions, that is, by purely electrical means without any need for a magnetic field, which is a crucial step towards high-density on-chip integration of superconducting quantum devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 22.806
Times cited: 102
DOI: 10.1038/nphys3240
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“Imaging of super-fast dynamics and flow instabilities of superconducting vortices”. Embon L, Anahory Y, Jelić, ZL, Lachman EO, Myasoedov Y, Huber ME, Mikitik GP, Silhanek AV, Milošević, MV, Gurevich A, Zeldov E, Nature communications 8, 85 (2017). http://doi.org/10.1038/S41467-017-00089-3
Abstract: Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which undergo cascades of bifurcations as the current and magnetic field increase. Our numerical simulations predict metamorphosis of fast Abrikosov vortices into mixed Abrikosov-Josephson vortices at even higher velocities. This work offers an insight into the fundamental physics of dynamic vortex states of superconductors at high current densities, crucial for many applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 12.124
Times cited: 124
DOI: 10.1038/S41467-017-00089-3
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“Superconducting diode effect via conformal-mapped nanoholes”. Lyu Y-Y, Jiang J, Wang Y-L, Xiao Z-L, Dong S, Chen Q-H, Milošević, MV, Wang H, Divan R, Pearson JE, Wu P, Peeters FM, Kwok W-K, Nature Communications 12, 2703 (2021). http://doi.org/10.1038/S41467-021-23077-0
Abstract: A superconducting diode is an electronic device that conducts supercurrent and exhibits zero resistance primarily for one direction of applied current. Such a dissipationless diode is a desirable unit for constructing electronic circuits with ultralow power consumption. However, realizing a superconducting diode is fundamentally and technologically challenging, as it usually requires a material structure without a centre of inversion, which is scarce among superconducting materials. Here, we demonstrate a superconducting diode achieved in a conventional superconducting film patterned with a conformal array of nanoscale holes, which breaks the spatial inversion symmetry. We showcase the superconducting diode effect through switchable and reversible rectification signals, which can be three orders of magnitude larger than that from a flux-quantum diode. The introduction of conformal potential landscapes for creating a superconducting diode is thereby proven as a convenient, tunable, yet vastly advantageous tool for superconducting electronics. This could be readily applicable to any superconducting materials, including cuprates and iron-based superconductors that have higher transition temperatures and are desirable in device applications. A superconducting diode is dissipationless and desirable for electronic circuits with ultralow power consumption, yet it remains challenging to realize it. Here, the authors achieve a superconducting diode in a conventional superconducting film patterned with a conformal array of nanoscale holes.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 12.124
Times cited: 71
DOI: 10.1038/S41467-021-23077-0
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“Effects of lateral asymmetry on electronic structure of strained semiconductor nanorings in a magnetic field”. Milošević, MM, Tadić, M, Peeters FM, Nanotechnology 19 (2008). http://doi.org/10.1088/0957-4484/19/45/455401
Abstract: The influence of lateral asymmetry on the electronic structure and optical transitions in elliptical strained InAs nanorings is analyzed in the presence of a perpendicular magnetic field. Two-dimensional rings are assumed to have elliptical inner and outer boundaries oriented in mutually orthogonal directions. The influence of the eccentricity of the ring on the energy levels is analyzed. For large eccentricity of the ring, we do not find any AharonovBohm effect, in contrast to circular rings. Rather, the single-particle states of the electrons and the holes are localized as in two laterally coupled quantum dots formed in the lobes of the nanoring. Our work indicates that the control of shape is important for the existence of the AharonovBohm effect in semiconductor nanorings.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.44
Times cited: 11
DOI: 10.1088/0957-4484/19/45/455401
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“In situ tailoring of superconducting junctions via electro-annealing”. Lombardo J, Jelić, ŽL, Baumans XDA, Scheerder JE, Nacenta JP, Moshchalkov VV, Van de Vondel J, Kramer RBG, Milošević, MV, Silhanek AV, Nanoscale 10, 1987 (2018). http://doi.org/10.1039/C7NR08571K
Abstract: We demonstrate the in situ engineering of superconducting nanocircuitry by targeted modulation of material properties through high applied current densities. We show that the sequential repetition of such customized electro-annealing in a niobium (Nb) nanoconstriction can broadly tune the superconducting critical temperature T-c and the normal-state resistance R-n in the targeted area. Once a sizable R-n is reached, clear magneto-resistance oscillations are detected along with a Fraunhofer-like field dependence of the critical current, indicating the formation of a weak link but with further adjustable characteristics. Advanced Ginzburg-Landau simulations fully corroborate this picture, employing the detailed parametrization from the electrical characterization and high resolution electron microscope images of the region within the constriction where the material has undergone amorphization by electro-annealing.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 7.367
Times cited: 23
DOI: 10.1039/C7NR08571K
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“First-principles exploration of superconductivity in MXenes”. Bekaert J, Sevik C, Milošević, MV, Nanoscale 12, 17354 (2020). http://doi.org/10.1039/D0NR03875J
Abstract: MXenes are an emerging class of two-dimensional materials, which in their thinnest limit consist of a monolayer of carbon or nitrogen (X) sandwiched between two transition metal (M) layers. We have systematically searched for superconductivity among MXenes for a range of transition metal elements, based on a full first-principles characterization in combination with the Eliashberg formalism. Thus, we identified six superconducting MXenes: three carbides (Mo2C, W2C and Sc2C) and three nitrides (Mo2N, W2N and Ta2N). The highest critical temperature of similar to 16 K is found in Mo2N, for which a successful synthesis method has been established [Urbankowskiet al.,Nanoscale, 2017,9, 17722-17730]. Moreover, W2N presents a novel case of competing superconducting and charge density wave phases.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 6.7
Times cited: 15
DOI: 10.1039/D0NR03875J
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“Enhancing superconductivity in MXenes through hydrogenation”. Bekaert J, Sevik C, Milošević, MV, Nanoscale 14, 9918 (2022). http://doi.org/10.1039/D2NR01939F
Abstract: Two-dimensional transition metal carbides and nitrides (MXenes) are an emerging class of atomically-thin superconductors, whose characteristics are highly prone to tailoring by surface functionalization. Here we explore the use of hydrogen adatoms to enhance phonon-mediated superconductivity in MXenes, based on first-principles calculations combined with Eliashberg theory. We first demonstrate the stability of three different structural models of hydrogenated Mo- and W-based MXenes. Particularly high critical temperatures of over 30 K are obtained for hydrogenated Mo2N and W2N. Several mechanisms responsible for the enhanced electron-phonon coupling are uncovered, namely (i) hydrogen-induced changes in the phonon spectrum of the host MXene, (ii) emerging hydrogen-based phonon modes, and (iii) charge transfer from hydrogen to the MXene layer, boosting the density of states at the Fermi level. Finally, we demonstrate that hydrogen adatoms are moreover able to induce superconductivity in MXenes that are not superconducting in pristine form, such as Nb2C.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 6.7
Times cited: 2
DOI: 10.1039/D2NR01939F
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“Strong gate-tunability of flat bands in bilayer graphene due to moiré, encapsulation between hBN monolayers”. Smeyers R, Milošević, MV, Covaci L, Nanoscale 15, 4561 (2023). http://doi.org/10.1039/D2NR07171A
Abstract: When using hexagonal boron-nitride (hBN) as a substrate for graphene, the resulting moire pattern creates secondary Dirac points. By encapsulating a multilayer graphene within aligned hBN sheets the controlled moire stacking may offer even richer benefits. Using advanced tight-binding simulations on atomistically-relaxed heterostructures, here we show that the gap at the secondary Dirac point can be opened in selected moire-stacking configurations, and is independent of any additional vertical gating of the heterostructure. On the other hand, gating can broadly tune the gap at the principal Dirac point, and may thereby strongly compress the first moire mini-band in width against the moire-induced gap at the secondary Dirac point. We reveal that in hBN-encapsulated bilayer graphene this novel mechanism can lead to isolated bands flatter than 10 meV under moderate gating, hence presenting a convenient pathway towards electronically-controlled strongly-correlated states on demand.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 6.7
DOI: 10.1039/D2NR07171A
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“Flattening conduction and valence bands for interlayer excitons in a moire MoS₂/WSe₂, heterobilayer”. Conti S, Chaves A, Pandey T, Covaci L, Peeters FM, Neilson D, Milošević, MV, Nanoscale , 1 (2023). http://doi.org/10.1039/D3NR01183F
Abstract: We explore the flatness of conduction and valence bands of interlayer excitons in MoS2/WSe2 van der Waals heterobilayers, tuned by interlayer twist angle, pressure, and external electric field. We employ an efficient continuum model where the moire pattern from lattice mismatch and/or twisting is represented by an equivalent mesoscopic periodic potential. We demonstrate that the mismatch moire potential is too weak to produce significant flattening. Moreover, we draw attention to the fact that the quasi-particle effective masses around the Gamma-point and the band flattening are reduced with twisting. As an alternative approach, we show (i) that reducing the interlayer distance by uniform vertical pressure can significantly increase the effective mass of the moire hole, and (ii) that the moire depth and its band flattening effects are strongly enhanced by accessible electric gating fields perpendicular to the heterobilayer, with resulting electron and hole effective masses increased by more than an order of magnitude – leading to record-flat bands. These findings impose boundaries on the commonly generalized benefits of moire twistronics, while also revealing alternative feasible routes to achieve truly flat electron and hole bands to carry us to strongly correlated excitonic phenomena on demand.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 6.7
Times cited: 1
DOI: 10.1039/D3NR01183F
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