Abstract
Two magnetic-field-induced quantum critical behaviors were recently discovered in two dimensional electron gas (2DEG) at LaTiO3/SrTiO3 interface and interpreted by disordered superconducting puddles coupled through 2DEG. In this scenario, the 2DEG is proposed to undergo a spontaneous phase separation and breaks up into locally superconducting puddles in a metallic matrix. However, as the inhomogeneous superconducting 2DEG is only illative, this proposal still lacks the direct experimental demonstration. Here, we artificially construct superconducting puddles-2DEG hybrid system by depositing tin nanoislands array on single crystalline monolayer graphene, where the two quantum critical behaviors are reproduced. Through the finite-size scaling analysis on magnetoresistivity, we show that the two quantum critical behaviors result from the intra-island and inter-island phase coherence, respectively, which are further illustrated by the phase diagram. This work provides a platform to study superconducting quantum phase transitions in a 2D system and helps to integrate superconducting devices into semiconductor technology.
Highlights
Two magnetic-field-induced quantum critical behaviors were recently discovered in two dimensional electron gas (2DEG) at LaTiO3/SrTiO3 interface and interpreted by disordered superconducting puddles coupled through 2DEG
The two quantum phase transition (QPT) emerged at LaTiO3/SrTiO3 interface were assumed to be related to the inhomogeneous superconductivity, in which one QPT corresponded to the local ordering of superconducting puddles formed by high-mobility carriers (HMCs) and the other QPT was due to the coherence between superconducting puddles coupled by 2DEG14
As the magnetic field can induce the vortex matter in both the intra-tin and intertin nanoisland superconductors, two QPTs can be observed in the Discussion Despite the two quantum critical behaviors are well built at H1* and H2*, respectively, the resistance scaling behavior at H1* holds only down to 2 K instead of approaching to the lowest temperature, in contrast to the H2*
Summary
Two magnetic-field-induced quantum critical behaviors were recently discovered in two dimensional electron gas (2DEG) at LaTiO3/SrTiO3 interface and interpreted by disordered superconducting puddles coupled through 2DEG. In this scenario, the 2DEG is proposed to undergo a spontaneous phase separation and breaks up into locally superconducting puddles in a metallic matrix. We artificially construct superconducting puddles-2DEG hybrid system by depositing tin nanoislands array on single crystalline monolayer graphene, where the two quantum critical behaviors are reproduced. The constructed H–T phase diagram further verifies the presence of two QPTs in graphene-tin nanoislands array hybrid
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
