Superconducting dome in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>MoS</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>TiSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>generated by quasiparticle-phonon coupling

Das, Tanmoy; Dolui, Kapildeb

doi:10.1103/physrevb.91.094510

Cited by 55 publications

(54 citation statements)

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“…Several groups have theoretically studied the superconducting dome of MoS 2 in a similar approach [19][20][21]. They first obtain electron-phonon coupling constants from first-principles calculations, and then estimate superconducting transition temperatures using the Allen-Dynes formula based on Eliashberg theory [22,23].…”

Section: Introductionmentioning

confidence: 99%

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂

2020

New J. Phys.

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We combine first-principles calculations, a three-band tight-binding model, and Bardeen-Cooper-Schrieffer theory to explore the physical mechanism for a dome-shaped dependence of superconducting transition temperature of monolayer MoS 2 on electron doping concentration, which has been observed experimentally (2012 Science 338 1193). We find that in the process of doping more electrons contribute to superconducting pairing, but above some doping value the effective attractive interaction decreases so greatly that it starts to reduce the pairing strength, forming a superconducting dome. Therefore, the dome behavior can be attributed to the competition between the growing Fermi pocket (corresponding to an increase of the number of intervalley phonon scatterings) and the screened intervalley phonon scattering (corresponding to a decrease of scattering probability).

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Section: Introductionmentioning

confidence: 99%

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂

2020

New J. Phys.

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“…As a consequence, the dependence of T c on the tuning parameter is usually rather weak in the non-CDW regime beyond the critical point 16,17,[20][21][22][23] . There is currently no clear evidence that quantum critical fluctuations associated with the CDW QCP have any effect on the SC 24 . Recently, the observation of ubiquitous charge ordering phenomena in cuprate high-temperature superconductors has boosted interest in the interplay between SC and charge ordering 25,26 .…”

Section: Substituting Pd For Pt Suppressesmentioning

confidence: 99%

Charge density wave quantum critical point with strong enhancement of superconductivity

et al. 2017

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led to a great interest in QCPs are the very unusual properties that are observed near a QCP, such as unconventional superconductivity (SC), non-Fermi-liquid or anomalous critical behaviour 3-6 . Quantum fluctuations are therefore suspected to cause these anomalous properties, but most aspects are far from being understood and are still the subject of active discussions. An issue that has attracted great interest is the appearance of unconventional SC observed at magnetic QCPs, that is where a magnetic ordered state is suppressed. Such unconventional SC states have been reported for very different kinds of compounds, for example heavy-fermion systems 3,7 , cuprates 8,9 and iron pnictides 10,11 . There is some evidence that backs up the hypothesis that the binding of electrons into the superconducting Cooper pairs is not mediated by phononic excitations as in classical superconductors, but by magnetic excitations connected to the disappearing magnetic order 12,13 . The fact that SC is observed only in the vicinity of the QCP and presents a strong dependence on the tuning parameter supports this hypothesis. It often results in a dome-like shape of the phase diagram of tuning parameter versus temperature.However, QCPs are not restricted to magnetic systems; they can be associated with any continuous phase transition. While searching for appropriate non-magnetic systems that show a QCP with associated SC, we looked at compounds that show a charge density wave (CDW) type of structural transition. CDW systems present an instability of the electronic states close to the Fermi level F , which results in a modulation of the electronic charges below a transition temperature T CDW (ref. 14). The modulation periodicity is usually associated with a nesting vector of the Fermi surface. Therefore, a gap opens in the electronic density of states (DOS) at F , N ( F ), below T CDW . In one-dimensional (1D) systems, for which such a transition was initially proposed, this effect changes the character of the system from metallic for T > T CDW to insulating for T < T CDW . In 2D or 3D systems, the gap opens only on a part of the Fermi surface and, therefore, the conductivity remains metallic below T CDW . The opening of the gap does, however, lead to a very characteristic upturn of the resistivity ρ(T ) at T CDW .Some CDW transitions can be tuned to a T = 0 critical point as well [15][16][17][18][19][20][21] . The appearance or a strengthening of a superconducting state is frequently found near the vanishing point of the CDW state, similar to magnetic QCPs. Yet, in this case, it can easily be explained within the standard BCS-based theories: the gap associated with the CDW closes at the critical point, resulting in an increase of N ( F ), which, in turn, leads to an increase of the SC transition temperature T c . As a consequence, the dependence of T c on the tuning parameter is usually rather weak in the non-CDW regime beyond the critical point 16,17,[20][21][22][23] . There is currently no clear evidence that quantum critical fluc...

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“…On the theory side, several mechanisms including purely electronic ones (called Coulomb driven hereafter) have been suggested to give rise to superconductivity, predicting unconventional 21,22 and possibly topologically non-trivial types of superconducting order 23 . In contrast, more conventional pathways to superconducting pairing resulting from electronphonon coupling have also been proposed [24][25][26] . However, in all of these scenarios it is unclear to which extent the renormalized Coulomb interactions affect superconductivity when approaching the monolayer limit.…”

Section: Introductionmentioning

confidence: 99%

“…We find this to be true independently of the dielectric environment of the substrate. For the scenario of phonon mediated SC [24][25][26] , we show that the phonon mediated electron-electron attraction generally overcomes the Coulomb repulsion when a Lifschitz transition takes place and additional Fermi pockets become available. The intrinsic screening of TMDCs at their superconducting transition is shown to be typically so large that it renders external substrate screening rather unimportant for the SC transition despite the atomic scale proximity of the substrate.…”

Section: Introductionmentioning

confidence: 99%

Interplay of screening and superconductivity in low-dimensional materials

et al. 2016

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A quantitative description of Coulomb interactions is developed for two-dimensional superconducting materials, enabling us to compare intrinsic with external screening effects, such as those due to substrates. Using the example of a doped monolayer of MoS 2 embedded in a tunable dielectric environment, we demonstrate that the influence of external screening is limited to a length scale, bounded from below by the effective thickness of the quasi two-dimensional material and from above by its intrinsic screening length. As a consequence, it is found that unconventional Coulomb driven superconductivity cannot be induced in MoS 2 by tuning the substrate properties alone. Our calculations of the retarded Morel-Anderson Coulomb potential µ * reveal that the Coulomb interactions, renormalized by the reduced layer thickness and the substrate properties, can shift the onset of the electron-phonon driven superconducting phase in monolayer MoS 2 but do not significantly affect the critical temperature at optimal doping.

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Superconducting dome inMoS2andTiSe2generated by quasiparticle-phonon coupling

Cited by 55 publications

References 50 publications

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂

Charge density wave quantum critical point with strong enhancement of superconductivity

Interplay of screening and superconductivity in low-dimensional materials

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Superconducting dome inMoS2andTiSe2generated by quasiparticle-phonon coupling

Cited by 55 publications

References 50 publications

Superconducting dome driven by intervalley phonon scattering in monolayer MoS2

Superconducting dome driven by intervalley phonon scattering in monolayer MoS2

Charge density wave quantum critical point with strong enhancement of superconductivity

Interplay of screening and superconductivity in low-dimensional materials

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Product

Resources

About

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂

Superconducting dome driven by intervalley phonon scattering in monolayer MoS₂