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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

Experimental evidence of pressure-induced superconductivity.(a) The temperature-dependent resistance under different pressures up to 16.1 GPa in run no. 1. The inset shows the temperature-dependent resistance from 1.8 to 300 K at 2.5 GPa. The onset of superconductivity can be seen from the drop in resistance. (b) Temperature dependence of resistance under various pressures from 9.3 to 68.5 GPa in run no. 2. (c) Magnetoresistance comparison at 10 K between ambient pressure and 2.5 GPa. Magnetoresistance is strongly suppressed with increasing pressure when superconductivity becomes predominant. (d) The real part of the a.c. susceptibility versus temperature at different pressures.
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f2: Experimental evidence of pressure-induced superconductivity.(a) The temperature-dependent resistance under different pressures up to 16.1 GPa in run no. 1. The inset shows the temperature-dependent resistance from 1.8 to 300 K at 2.5 GPa. The onset of superconductivity can be seen from the drop in resistance. (b) Temperature dependence of resistance under various pressures from 9.3 to 68.5 GPa in run no. 2. (c) Magnetoresistance comparison at 10 K between ambient pressure and 2.5 GPa. Magnetoresistance is strongly suppressed with increasing pressure when superconductivity becomes predominant. (d) The real part of the a.c. susceptibility versus temperature at different pressures.

Mentions: Figure 2a,b shows the evolution of the resistance as a function of temperature in a single crystal of WTe2 at various pressures. The pressure was increased from 2.5 to 16.1 GPa in run no. 1 as shown in Fig. 2a, and from 9.3 to 68.5 GPa for another crystal in run no. 2 as shown in Fig. 2b. In run no. 1, at a pressure of 2.5 GPa, the resistance decreased monotonically with decreasing temperature, exhibiting typical metallic behaviour (inset of Fig. 2a). A superconducting transition was observed at Tc=3.1 K. Here we define Tc to be the onset temperature at which the drop in resistance occurs. At pressures up to 16.1 GPa, Tc increased with increasing applied pressure. In the pressure curves for 2.5, 4.9 and 8.45 GPa, zero resistance was not seen because the superconducting transition was not complete at the lowest temperatures achievable using our equipment. If one check Fig. 2a carefully, it can be seen that the broadening widths at higher pressures are around 2 K. If such broadening keeps in the low pressure <8.45 GPa, the zero-resistance temperature will be extended below 1.8 K, which is the low limit of our equipment. At 11 GPa, however, zero resistance was observed for some temperatures. In the case of run no. 2, with pressures starting at 9.3 GPa, Tc first increased slightly to a maximum of 7 K at 16.8 GPa, where it began to decrease monotonically with increasing pressure as shown in Fig. 2b. A suppression of two to three orders of magnitude of the MR emerged once superconductivity appeared, as evidenced by the MR curves at 10 K shown in Fig. 2c. To demonstrate that the zero resistance represented superconductivity, we also performed a.c. susceptibility measurements as shown in Fig. 2d, where the diamagnetic signal was observed at 8.3 and 12.5 GPa. This is in good agreement with the resistance measurements. The onset of MR suppression and superconductivity under pressure were thus demonstrated.


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)

Experimental evidence of pressure-induced superconductivity.(a) The temperature-dependent resistance under different pressures up to 16.1 GPa in run no. 1. The inset shows the temperature-dependent resistance from 1.8 to 300 K at 2.5 GPa. The onset of superconductivity can be seen from the drop in resistance. (b) Temperature dependence of resistance under various pressures from 9.3 to 68.5 GPa in run no. 2. (c) Magnetoresistance comparison at 10 K between ambient pressure and 2.5 GPa. Magnetoresistance is strongly suppressed with increasing pressure when superconductivity becomes predominant. (d) The real part of the a.c. susceptibility versus temperature at different pressures.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Experimental evidence of pressure-induced superconductivity.(a) The temperature-dependent resistance under different pressures up to 16.1 GPa in run no. 1. The inset shows the temperature-dependent resistance from 1.8 to 300 K at 2.5 GPa. The onset of superconductivity can be seen from the drop in resistance. (b) Temperature dependence of resistance under various pressures from 9.3 to 68.5 GPa in run no. 2. (c) Magnetoresistance comparison at 10 K between ambient pressure and 2.5 GPa. Magnetoresistance is strongly suppressed with increasing pressure when superconductivity becomes predominant. (d) The real part of the a.c. susceptibility versus temperature at different pressures.
Mentions: Figure 2a,b shows the evolution of the resistance as a function of temperature in a single crystal of WTe2 at various pressures. The pressure was increased from 2.5 to 16.1 GPa in run no. 1 as shown in Fig. 2a, and from 9.3 to 68.5 GPa for another crystal in run no. 2 as shown in Fig. 2b. In run no. 1, at a pressure of 2.5 GPa, the resistance decreased monotonically with decreasing temperature, exhibiting typical metallic behaviour (inset of Fig. 2a). A superconducting transition was observed at Tc=3.1 K. Here we define Tc to be the onset temperature at which the drop in resistance occurs. At pressures up to 16.1 GPa, Tc increased with increasing applied pressure. In the pressure curves for 2.5, 4.9 and 8.45 GPa, zero resistance was not seen because the superconducting transition was not complete at the lowest temperatures achievable using our equipment. If one check Fig. 2a carefully, it can be seen that the broadening widths at higher pressures are around 2 K. If such broadening keeps in the low pressure <8.45 GPa, the zero-resistance temperature will be extended below 1.8 K, which is the low limit of our equipment. At 11 GPa, however, zero resistance was observed for some temperatures. In the case of run no. 2, with pressures starting at 9.3 GPa, Tc first increased slightly to a maximum of 7 K at 16.8 GPa, where it began to decrease monotonically with increasing pressure as shown in Fig. 2b. A suppression of two to three orders of magnitude of the MR emerged once superconductivity appeared, as evidenced by the MR curves at 10 K shown in Fig. 2c. To demonstrate that the zero resistance represented superconductivity, we also performed a.c. susceptibility measurements as shown in Fig. 2d, where the diamagnetic signal was observed at 8.3 and 12.5 GPa. This is in good agreement with the resistance measurements. The onset of MR suppression and superconductivity under pressure were thus demonstrated.

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