Punjab researchers develop transparent spintronic interface for quantum devices

New Delhi: Scientists at the Institute of Nano Science and Technology (INST) in Mohali, an autonomous research institution under the Department of Science and Technology (DST), have successfully produced a transparent conducting interface between two insulating materials.

This interface hosts a two-dimensional electron gas (2DEG) with room temperature spin polarisation, enabling the creation of see-through devices that efficiently conduct spin currents.

Led by Prof. Suvankar Chakraverty at the INST, the team achieved this by growing superlattices and heterostructures of oxide materials, specifically the chemicals LaFeO3 and SrTiO3.

The researchers developed an innovative transparent layer between two insulating materials that allows electrons to move in a two-dimensional plane at room temperature with their spins -- an intrinsic property of electrons -- aligned in the same direction. This breakthrough could revolutionise data transfer in electronic devices and significantly increase data storage capacity in quantum devices.

The quest for new functionalities in modern electronics has led scientists to explore the manipulation of the electron's spin degree of freedom, alongside its charge, giving rise to a new field known as spintronics. Although spintronics has long held theoretical promise, its exotic behaviours -- such as spin currents and manipulation -- remained elusive until recently.

Advances in materials and fabrication techniques at the nanoscale have enabled the creation of condensed matter systems exhibiting these properties, paving the way for a new era of spintronic devices with capabilities beyond traditional electronics.

The LaFeO3-SrTiO3 interface, exhibiting room temperature spin polarisation, showed unusual phenomena such as negative magnetoresistance and the anomalous Hall effect due to a structural transition in SrTiO3 at the interface. These features are crucial for spintronic quantum-device applications.

By manipulating spin in transparent materials, the researchers have unlocked new possibilities for light-controlled spintronics, which are impossible with traditional charge-based devices. This transparency allows for the integration of spintronic devices within existing displays or solar cells, potentially leading to advanced device architectures like transparent phone screens that process information with spin currents or solar cells that both generate electricity and manipulate spin.

The realisation of a conducting transparent oxide interface with spin polarisation at high temperatures may open up new frontiers in quantum-device physics, particularly in the fields of transparent spin-electronics, dissipation-less electronics, and quantum devices applicable for next-generation data storage and quantum computing.