Dimensionality-Driven Anomalous Metallic State with Zero-Field Nonreciprocal Transport in Layered Ising...

Area of Science:

• Condensed Matter Physics
• Quantum Materials Science

Background:

• Anomalous metal states (AMS) in
• failed
• superconductors offer insights into quantum criticality.
• Layered transition metal dichalcogenide (TMD) superconductors are studied for enhanced phase fluctuations and electronic correlations near the 2D limit.
• Field-free AMS and superconducting diode effects in TMDs remain largely unexplored.

Purpose of the Study:

• To investigate dimensionality-tunable anomalous metal states (AMS) in layered TMD superconductors.
• To explore the emergence of exotic quantum phenomena, including field-free superconducting diode effects, as systems approach the 2D limit.

Main Methods:

• Fabrication and characterization of layered 2H-Ta_{2}S_{3}Se thin films with tunable thickness down to 3 nm.
• Electrical transport measurements, including Hall resistance and longitudinal resistance, under varying magnetic fields and temperatures.
• Analysis of transport data to identify AMS characteristics and nonreciprocal transport behaviors.

Main Results:

• Demonstrated magnetic field-driven AMS in 2H-Ta_{2}S_{3}Se films thicker than 10 nm, characterized by vanishing Hall resistance and finite longitudinal resistance.
• Observed an emergent zero-field AMS in films as thin as 3 nm, consistent with the quantum vortex creep model.
• Exhibited nonreciprocal transport behaviors in the zero-field AMS, indicating spontaneous time-reversal symmetry breaking and vortex motion.

Conclusions:

• The study reports the first observation of a field-free AMS in a layered TMD superconductor, 2H-Ta_{2}S_{3}Se.
• Dimensionality tuning is crucial for observing AMS and associated exotic quantum phenomena, including zero-field superconducting diode effects.
• Findings open new avenues for exploring dimensionality-driven quantum critical phases and understanding field-free superconducting diode mechanisms.