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Pressure-driven dome-shaped superconductivity and electronic structural evolution in tungsten ditelluride.

Pan XC, Chen X, Liu H, Feng Y, Wei Z, Zhou Y, Chi Z, Pi L, Yen F, Song F, Wan X, Yang Z, Wang B, Wang G, Zhang Y - Nat Commun (2015)

Bottom Line: Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully.Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase.From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability.

View Article: PubMed Central - PubMed

Affiliation: 1] National Laboratory of Solid State Microstructures, College of Physics, Nanjing University, Nanjing 210093, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.

ABSTRACT
Tungsten ditelluride has attracted intense research interest due to the recent discovery of its large unsaturated magnetoresistance up to 60 T. Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully. Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase. From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability. Thus, tungsten ditelluride may provide a new platform for our understanding of superconductivity phenomena in transition metal dichalcogenides.

No MeSH data available.


Related in: MedlinePlus

WTe2 transport measurements at ambient pressure.(a) The atomic structure of the WTe2 crystal. Blue and green circles represent W and Te, respectively. (b) Temperature dependence of electrical resistivity at ambient pressure. The inset shows detail of data below 50 K with no hint of any superconductivity. (c) The magnetoresistance (upper plot) and Hall resistivity (down plot) at different temperatures at ambient pressure. Different colours represent different temperatures as marked.
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f1: WTe2 transport measurements at ambient pressure.(a) The atomic structure of the WTe2 crystal. Blue and green circles represent W and Te, respectively. (b) Temperature dependence of electrical resistivity at ambient pressure. The inset shows detail of data below 50 K with no hint of any superconductivity. (c) The magnetoresistance (upper plot) and Hall resistivity (down plot) at different temperatures at ambient pressure. Different colours represent different temperatures as marked.

Mentions: As shown in Fig. 1a, WTe2 is a layered TMD material and the layer stacking results in a unit cell with four formula units and orthorhombic symmetry (its space group is Pnm21)21. The Te–Te bonds between the Te–W–Te sandwich layers are weak; therefore, nanoflakes with thicknesses down to several nanometres can be exfoliated using a scotch tape-based mechanical method. Moreover, the W atoms form zigzag chains along the a axis resulting in a one-dimensional substructure within a 2D material1. We grew single crystals of WTe2 using a vapour transport method, in which the structural parameters were obtained by X-ray diffraction. As seen in the Supplementary Tables 1 and 2, WTe2 exhibits similar atomic structures to those reported previously21. At ambient pressure, the resistivity decreases smoothly with decreasing temperature as shown in Fig. 1b. No phase transition was observed down to 2 K. Figure 1c shows the magnetic field-dependent transport measured for various temperatures at ambient pressure, which confirms the large MR reported recently12.


Pressure-driven dome-shaped superconductivity and electronic structural evolution in tungsten ditelluride.

Pan XC, Chen X, Liu H, Feng Y, Wei Z, Zhou Y, Chi Z, Pi L, Yen F, Song F, Wan X, Yang Z, Wang B, Wang G, Zhang Y - Nat Commun (2015)

WTe2 transport measurements at ambient pressure.(a) The atomic structure of the WTe2 crystal. Blue and green circles represent W and Te, respectively. (b) Temperature dependence of electrical resistivity at ambient pressure. The inset shows detail of data below 50 K with no hint of any superconductivity. (c) The magnetoresistance (upper plot) and Hall resistivity (down plot) at different temperatures at ambient pressure. Different colours represent different temperatures as marked.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525151&req=5

f1: WTe2 transport measurements at ambient pressure.(a) The atomic structure of the WTe2 crystal. Blue and green circles represent W and Te, respectively. (b) Temperature dependence of electrical resistivity at ambient pressure. The inset shows detail of data below 50 K with no hint of any superconductivity. (c) The magnetoresistance (upper plot) and Hall resistivity (down plot) at different temperatures at ambient pressure. Different colours represent different temperatures as marked.
Mentions: As shown in Fig. 1a, WTe2 is a layered TMD material and the layer stacking results in a unit cell with four formula units and orthorhombic symmetry (its space group is Pnm21)21. The Te–Te bonds between the Te–W–Te sandwich layers are weak; therefore, nanoflakes with thicknesses down to several nanometres can be exfoliated using a scotch tape-based mechanical method. Moreover, the W atoms form zigzag chains along the a axis resulting in a one-dimensional substructure within a 2D material1. We grew single crystals of WTe2 using a vapour transport method, in which the structural parameters were obtained by X-ray diffraction. As seen in the Supplementary Tables 1 and 2, WTe2 exhibits similar atomic structures to those reported previously21. At ambient pressure, the resistivity decreases smoothly with decreasing temperature as shown in Fig. 1b. No phase transition was observed down to 2 K. Figure 1c shows the magnetic field-dependent transport measured for various temperatures at ambient pressure, which confirms the large MR reported recently12.

Bottom Line: Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully.Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase.From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability.

View Article: PubMed Central - PubMed

Affiliation: 1] National Laboratory of Solid State Microstructures, College of Physics, Nanjing University, Nanjing 210093, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.

ABSTRACT
Tungsten ditelluride has attracted intense research interest due to the recent discovery of its large unsaturated magnetoresistance up to 60 T. Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully. Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase. From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability. Thus, tungsten ditelluride may provide a new platform for our understanding of superconductivity phenomena in transition metal dichalcogenides.

No MeSH data available.


Related in: MedlinePlus