Enhanced Superconductivity Induced by the Hexagonal-Array-Cooling-Shrinkage Effect

Doping impurity into ZnO is an effective and powerful technique to tailor structures and enhance its optical properties. In this work, Zn1−xMgxO and Zn1−x−yMgxByO nanoparticles (x = 0, 0.1, 0.2, 0.3, 0.4; y = 0, 0.02, 0.04) were synthesized via one-pot method. It shows that the Mg and B dopants has great influence on crystallinity and surface morphology of ZnO nanoparticles, without changing the wurtzite structure of ZnO. The band structure study indicates that the competition of Conductive Band (CB) shift, Burstein–Moss (B-M) shift and Shrinkage effect will cause the band gap energy change in ZnO.

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Spectral properties and enhanced superconductivity in renormalized Migdal-Eliashberg theory

Physical Review B ◽

10.1103/physrevb.103.024520 ◽

2021 ◽

Vol 103 (2) ◽

Author(s):

Benjamin Nosarzewski ◽

Michael Schüler ◽

Thomas P. Devereaux

Keyword(s):

Spectral Properties ◽

Eliashberg Theory ◽

Enhanced Superconductivity

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Structural phase transition and superconductivity hierarchy in 1T-TaS2 under pressure up to 100 GPa

npj Quantum Materials ◽

10.1038/s41535-021-00320-x ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Qing Dong ◽

Quanjun Li ◽

Shujia Li ◽

Xuhan Shi ◽

Shifeng Niu ◽

...

Keyword(s):

Structural Phase ◽

Transition Metal Dichalcogenides ◽

Phonon Coupling ◽

Structural Phase Transitions ◽

Strong Electron ◽

Electron Phonon Coupling ◽

Increasing Trend ◽

Metal Dichalcogenides ◽

Dome Shape ◽

Enhanced Superconductivity

AbstractThe adoption of high pressure not only reinforces the comprehension of the structure and exotic electronic states of transition metal dichalcogenides (TMDs) but also promotes the discovery of intriguing phenomena. Here, 1T-TaS2 was investigated up to 100 GPa, and re-enhanced superconductivity was found with structural phase transitions. The discovered I4/mmm TaS2 presents strong electron–phonon coupling, revealing a good superconductivity of the nonlayered structure. The P–T phase diagram shows a dome shape centered at ~20 GPa, which is attributed to the distortion of the 1T structure. Accompanied by the transition to nonlayered structure above 44.5 GPa, the superconducting critical temperature shows an increasing trend and reaches ~7 K at the highest studied pressure, presenting superior superconductivity compared to the original layered structure. It is unexpected that the pressure-induced re-enhanced superconductivity was observed in TMDs, and the transition from a superconductor with complicated electron-pairing mechanism to a phonon-mediated superconductor would expand the field of pressure-modified superconductivity.

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