Friday 28 March 2025
Researchers have made a significant breakthrough in the field of spintronics, achieving record-high non-local spin signals and nanosecond spin lifetimes in ultra-thin black phosphorus (BP). This feat has far-reaching implications for the development of novel spin-based devices that can perform complex functions such as logic, communication, and storage.
Spintronics is a relatively new field that focuses on manipulating the intrinsic angular momentum of electrons, known as spin, to create new electronic devices. Unlike traditional electronics, which rely solely on charge flow, spintronics has the potential to revolutionize computing by enabling faster, more efficient, and more secure data processing.
To achieve this breakthrough, scientists fabricated ultra-thin BP layers, just 8 nanometers thick, using a technique called van der Waals bonding. This unique material exhibits exceptional electronic mobility and spin properties, making it an ideal candidate for spintronics applications.
The researchers then integrated the BP layer with two insulating materials: hexagonal boron nitride (hBN) and silicon dioxide (SiO2). The hBN substrate was used to create a high-quality tunnel barrier, while the SiO2 substrate enabled the formation of a p-n junction. This combination allowed for the manipulation of charge carriers in the BP layer, enabling the observation of spin transport phenomena.
Using a non-local geometry, the researchers injected a spin current into the BP layer and detected it using a second electrode pair. The resulting spin signal was found to be record-high, with amplitudes reaching 320 ohms in the hole-dominant regime. This is a significant improvement over previous results obtained in other materials, such as graphene.
Moreover, the researchers were able to extract spin lifetimes exceeding nanoseconds in both electron and hole regimes. In fact, the spin lifetime of holes was found to be approximately 16.1 nanoseconds, which is comparable to the longest spin lifetimes previously recorded in graphene and n-type silicon.
These results have significant implications for the development of spin-based devices. For instance, they could enable the creation of ultra-fast and energy-efficient logic gates, as well as high-performance storage devices that can process large amounts of data quickly and securely.
The researchers also explored the temperature dependence of spin transport in BP. They found that the spin lifetime remained relatively constant between 1.6 Kelvin and room temperature, which is a significant advantage over other materials that often suffer from spin relaxation at higher temperatures.
Cite this article: “Record-High Non-Local Spin Signals in Ultra-Thin Black Phosphorus for Next-Generation Spintronics Devices”, The Science Archive, 2025.
Spintronics, Black Phosphorus, Ultra-Thin Layers, Van Der Waals Bonding, Hexagonal Boron Nitride, Silicon Dioxide, Tunnel Barrier, P-N Junction, Spin Transport, Nanosecond Spin Lifetimes
