# Anomalous Enhancement of Upper Critical Field in Sr2RuO4 Thin Films

## TL;DR

This study reports a significant enhancement of the upper critical magnetic field in Sr2RuO4 thin films, indicating altered superconducting properties possibly linked to a triplet d-vector rotation, advancing understanding of exotic superconductivity.

## Contribution

It reveals a dramatic enhancement of Hc2 in Sr2RuO4 thin films due to dimensional crossover, differing from bulk behavior and suggesting new superconducting phenomena.

## Key findings

- Hc2 is dramatically enhanced in thin films compared to bulk
- The enhancement follows a distinct relation from bulk Hc2 and transition temperature
- Possible rotation of the triplet d-vector associated with the enhancement

## Abstract

We report large enhancement of upper critical field Hc2 observed in superconducting Sr2RuO4 thin films. Through dimensional crossover approaching two dimensions, Hc2 except the in-plane field direction is dramatically enhanced compared to bulks, following a definite relation distinct from bulk one between Hc2 and the transition temperature. The anomalous enhancement of Hc2 is highly suggestive of important changes of the superconducting properties, possibly accompanied with rotation of the triplet d-vector. Our findings will become a crucial step to further explore exotic properties by employing Sr2RuO4 thin films.