The electronic detection of quantum spin fluctuations in pyrochlore heterostructures*

While the rise of quantum computers may one day help solve complex problems and deliver information with unhackable security, there is lack of a material platforms for scalable realization of quantum technologies. For instance, the most interesting magnetic property of the celebrated quantum spin liquids (QSLs) is the possibility of quantum mechanical encryption and transport of information, protected against environmental influences. Despite extensive studies on QSLs, they are still far away from applications. One obstacle is that most of the studied QSLs are insulators and electronically inert, which is incompatible with an electrical circuit that relies on moving charge carriers. The grand challenge is to find a way to convert the entanglement information into mobile charge signal by “metallizing” quantum magnets.

 

In this talk, I will introduce a unique approach by designing and synthesizing new epitaxial heterostructures based on geometrically frustrated magnets to address this obstacle. I will give two examples: (i) Bi₂Ir₂O₇/Dy₂Ti₂O₇ (BIO/DTO) heterostructure in which the thin BIO film was deposited on DTO single crystal. The transport data measured on the BIO thin film reflects the Kagome spin ice broken phase transition of the underlying DTO crystal; (ii) Bi₂Ir₂O₇/Yb₂Ti₂O₇ (BIO/YbTO) heterostructure in which the abnormal magnetoresistance of the BIO film, the scaling behavior of both the temperature and magnetic field dependences, strongly correlates to the strong quantum spin fluctuations in Yb₂Ti₂O₇ crystal.