Limits...
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

Density functional theory calculations.(a) The pressure dependence of the lattice parameters (upper) and c/a ratio obtained from geometry optimization (lower). (b) The calculated evolution of the Fermi surface contour at various pressures (marked in the plot).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4525151&req=5

f4: Density functional theory calculations.(a) The pressure dependence of the lattice parameters (upper) and c/a ratio obtained from geometry optimization (lower). (b) The calculated evolution of the Fermi surface contour at various pressures (marked in the plot).

Mentions: We performed total energy calculations for a number of different volumes to simulate the high pressure conditions in WTe2. We optimized the lattice parameters and all the independent internal atomic coordinates for each volume. The obtained volumes versus the total energy behaviour were found to be in good agreement with the Murnaghan equation of state as shown in the Supplementary Fig. 3 (ref. 28). Our theoretical equilibrium unit cell volume (314 Å3) is only about 2.6% larger than the experimental value (306 Å3). Such deviation exists normally in generalized gradient approximation calculations. Our numerical bulk modulus at equilibrium B0 was 56 GPa, slightly larger than that of MoS2 (ref. 29). In Fig. 4a, we show the pressure dependence of the lattice parameter and the c/a ratio. The 2D nature of this compound is clearly exemplified from the different rates of compressibility along the c axis and in the ab plane. The numerical c/a ratio first decreases with pressure until a minimum value is reached at 30 GPa. An upward shift can then be seen, similar to the case for MoS2 (ref. 17). In MoS2, this abnormality was attributed to the occurrence of an isostructural phase transition17.


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)

Density functional theory calculations.(a) The pressure dependence of the lattice parameters (upper) and c/a ratio obtained from geometry optimization (lower). (b) The calculated evolution of the Fermi surface contour at various pressures (marked in the plot).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: Density functional theory calculations.(a) The pressure dependence of the lattice parameters (upper) and c/a ratio obtained from geometry optimization (lower). (b) The calculated evolution of the Fermi surface contour at various pressures (marked in the plot).
Mentions: We performed total energy calculations for a number of different volumes to simulate the high pressure conditions in WTe2. We optimized the lattice parameters and all the independent internal atomic coordinates for each volume. The obtained volumes versus the total energy behaviour were found to be in good agreement with the Murnaghan equation of state as shown in the Supplementary Fig. 3 (ref. 28). Our theoretical equilibrium unit cell volume (314 Å3) is only about 2.6% larger than the experimental value (306 Å3). Such deviation exists normally in generalized gradient approximation calculations. Our numerical bulk modulus at equilibrium B0 was 56 GPa, slightly larger than that of MoS2 (ref. 29). In Fig. 4a, we show the pressure dependence of the lattice parameter and the c/a ratio. The 2D nature of this compound is clearly exemplified from the different rates of compressibility along the c axis and in the ab plane. The numerical c/a ratio first decreases with pressure until a minimum value is reached at 30 GPa. An upward shift can then be seen, similar to the case for MoS2 (ref. 17). In MoS2, this abnormality was attributed to the occurrence of an isostructural phase transition17.

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