0000000000740148
AUTHOR
M. R. Osorio
Scanning tunneling measurements of layers of superconducting 2H-TaSe2: Evidence for a zero-bias anomaly in single layers
This work was supported by the EU (ERC Advanced Grant SPINMOL and COST MP-1201), the Spanish MINECO (Consolider-Ingenio in Molecular Nanoscience, CSD2007-00010 and projects FIS2011-23488, MAT2011-25046, MAT2011-22785 and ACI-2009-0905, co-financed by FEDER), by the Comunidad de Madrid (program Nanobiomagnet) and the Generalitat Valenciana (Programs Prometeo and ISIC-NANO)
Strong enhancement of superconductivity at high pressures within the charge-density-wave states of2H−TaS2and2H−TaSe2
We present measurements of the superconducting and charge density wave critical temperatures (Tc and TCDW) as a function of pressure in the transition metal dichalchogenides 2H-TaSe2 and 2H-TaS2. Resistance and susceptibility measurements show that Tc increases from temperatures below 1 K up to 8.5 K at 9.5 GPa in 2H-TaS2 and 8.2 K at 23 GPa in 2H-TaSe2. We observe a kink in the pressure dependence of TCDW at about 4 GPa that we attribute to the lock-in transition from incommensurate CDW to commensurate CDW. Above this pressure, the commensurate TCDW slowly decreases coexisting with superconductivity within our full pressure range.
Scanning tunneling spectroscopy of layers of superconducting 2H-TaSe$_\textbf{2}$: Evidence for a zero bias anomaly in single layers
We report a characterization of surfaces of the dichalcogenide TaSe$_2$ using scanning tunneling microscopy and spectroscopy (STM/S) at 150 mK. When the top layer has the 2H structure and the layer immediately below the 1T structure, we find a singular spatial dependence of the tunneling conductance below 1 K, changing from a zero bias peak on top of Se atoms to a gap in between Se atoms. The zero bias peak is additionally modulated by the commensurate $3a_0 \times 3a_0$ charge density wave of 2H-TaSe$_2$. Multilayers of 2H-TaSe$_2$ show a spatially homogeneous superconducting gap with a critical temperature also of 1 K. We discuss possible origins for the peculiar tunneling conductance in …
Scanning tunneling measurements of layers of superconducting 2H-TaSe 2: Evidence for a zero-bias anomaly in single layers
We report a characterization of surfaces of the dichalcogenide TaSe2 using scanning tunneling microscopy and spectroscopy at 150 mK. When the top layer has the 2H structure and the layer immediately below the 1T structure, we find a singular spatial dependence of the tunneling conductance below 1 K, changing from a zero-bias peak on top of Se atoms to a gap in between Se atoms. The zero-bias peak is additionally modulated by the commensurate 3a0 × 3a0 charge-density wave of 2H-TaSe2. Multilayers of 2H-TaSe2 show a spatially homogeneous superconducting gap with a critical Temperature also of 1 K. We discuss possible origins for the peculiar tunneling conductance in single layers