Pure nematic quantum critical point accompanied by a superconducting dome

Area of Science:

• Condensed matter physics
• Quantum criticality
• Superconductivity

Background:

• Quantum critical points (QCPs) are central to condensed matter physics.
• Symmetry-breaking order near QCPs intensifies quantum fluctuations, potentially leading to unconventional superconductivity.
• Superconducting domes are often observed near magnetic QCPs, supporting spin fluctuation-driven superconductivity.

Purpose of the Study:

• To investigate whether a nonmagnetic QCP, specifically electronic nematic order, can promote superconductivity in real materials.
• To experimentally demonstrate the existence of a pure nematic QCP in nonmagnetic FeSe$_{x}$Te$_{y}$.

Main Methods:

• Experimental investigation of nonmagnetic FeSe$_{x}$Te$_{y}$.
• Analysis of electronic nematic order and its associated quantum critical point.

Main Results:

• Experimental demonstration of a pure nematic quantum critical point (QCP) in nonmagnetic FeSe$_{x}$Te$_{y}$.
• The nematic QCP is located near the center of a superconducting dome.
• Evidence that nematic fluctuations enhanced around the nematic QCP can boost superconductivity.

Conclusions:

• Nematic fluctuations associated with a pure nematic QCP can drive superconductivity.
• This finding provides experimental evidence for the role of nonmagnetic electronic nematic order in promoting superconductivity.