The reality of Moore’s law’s decline is no longer doubted for good empirical reasons. That said, never say never. Recent work by Lawrence Berkeley National Laboratory researchers suggests heterostructure oxides may breathe life into Moore’s maxim which predicts the number of transistors packed into a tiny silicon-based computer chip would double every two years.
“Scientists have long known that oxide materials, on their own, are typically insulating – which means that they are not electrically conductive. When two oxide materials are layered together to form a heterostructure, new electronic properties such as superconductivity – the state in which a material can conduct electricity without resistance, typically at hundreds of degrees below freezing – and magnetism somehow form at their interface, which is the juncture where two materials meet. But very little is known about how to control these electronic states because few techniques can probe below the interface,” reports Theresa Duque in an article on the LBNL website.
“Now, the Berkeley Lab-led team – directed by Alessandra Lanzara, a senior faculty scientist in Berkeley Lab’s Materials Sciences Division and professor of physics at UC Berkeley – has demonstrated a technique that sheds light on the production of new exotic states, such as superconductivity from atomically thin oxide heterostructures.”
The researchers’ work was reported earlier in Nature Communications.
Working with Berkeley Lab’s Advanced Light Source, researchers used a technique called angle-resolved photoemission spectroscopy (ARPES) to directly measure the electronic structure of electrons confined between layers of a strontium titanate/samarium titanate heterostructure. “Probing at a depth of approximately 1 nanometer (a billionth of a meter) inside the sample, the researchers discovered two unique electronic properties – called a Van Hove singularity (VHS) and Fermi surface topology – which condensed matter physicists have long considered important features for tuning superconductivity and other such exotic electronic states in electronic materials,” according to the LBNL article.
“Our findings add new pieces of information to this young field. While the road toward the industrial use of oxide electronics is still far, our work is a step forward in the development of next-generation alternatives to traditional electronics beyond Moore’s Law,” said lead author Ryo Mori, a doctoral researcher in Berkeley Lab’s Materials Sciences Division and Ph.D. student in physics at UC Berkeley.
Link to full article: https://newscenter.lbl.gov/2020/07/08/hidden-world-of-quantum-states/
Link to Nature report: https://www.nature.com/articles/s41467-019-13046-z