Information in computer systems is transmitted by means of semiconductors by the motion of electrons and saved within the course of the electron spin in magnetic supplies. To shrink gadgets whereas enhancing their efficiency—a purpose of an rising subject known as spin-electronics (“spintronics”)—researchers are trying to find distinctive supplies that mix each quantum properties. Writing in Nature Materials, a crew of chemists and physicists at Columbia finds a powerful hyperlink between electron transport and magnetism in a cloth known as chromium sulfide bromide (CrSBr).
Created within the lab of Chemist Xavier Roy, CrSBr is a so-called van der Waals crystal that may be peeled into stackable, 2D layers which might be only a few atoms skinny. Unlike associated supplies which might be shortly destroyed by oxygen and water, CrSBr crystals are steady at ambient situations. These crystals additionally preserve their magnetic properties on the comparatively excessive temperature of -280F, avoiding the necessity for costly liquid helium cooled to a temperature of -450F,
“CrSBr is infinitely easier to work with than other 2D magnets, which lets us fabricate novel devices and test their properties,” mentioned Evan Telford, a postdoc within the Roy lab who graduated with a PhD in physics from Columbia in 2020. Last yr, colleagues Nathan Wilson and Xiaodong Xu on the University of Washington and Xiaoyang Zhu at Columbia discovered a hyperlink between magnetism and the way CrSBr responds to gentle. In the present work, Telford led the trouble to discover its digital properties.
The crew used an electrical subject to review CrSBr layers throughout completely different electron densities, magnetic fields, and temperatures—completely different parameters that may be adjusted to supply completely different results in a cloth. As digital properties in CrSBr modified, so did its magnetism.
“Semiconductors have tunable electronic properties. Magnets have tunable spin configurations. In CrSBr, these two knobs are combined,” mentioned Roy. “That makes CrSBr engaging for each basic analysis and for potential spintronics utility.”
Magnetism is a tough property to measure straight, significantly as the dimensions of the fabric shrinks, defined Telford, nevertheless it’s simple to measure how electrons transfer with a parameter known as resistance. In CrSBr, resistance can function a proxy for in any other case unobservable magnetic states. “That’s very powerful,” mentioned Roy, particularly as researchers look to someday construct chips out of such 2D magnets, which might be used for quantum computing and to retailer large quantities of knowledge in a small area.
The hyperlink between the fabric’s digital and magnetic properties was on account of defects within the layers—for the crew, a fortunate break, mentioned Telford. “People usually want the ‘cleanest’ material possible. Our crystals had defects, but without those, we wouldn’t have observed this coupling,” he mentioned.
From right here, the Roy lab is experimenting with methods to develop peelable van der Waals crystals with deliberate defects, to enhance the flexibility to fine-tune the fabric’s properties. They are additionally exploring whether or not completely different combos of components might perform at increased temperatures whereas nonetheless retaining these precious mixed properties.
Evan J. Telford et al, Coupling between magnetic order and cost transport in a two-dimensional magnetic semiconductor, Nature Materials (2022). DOI: 10.1038/s41563-022-01245-x
Columbia University Quantum Initiative
Unique quantum materials might allow ultra-powerful, compact computer systems (2022, May 20)
retrieved 20 May 2022
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