“The whole is more than the sum of its parts.” These are the now-familiar words of Nobel prize winner Philip W. Anderson, and they have special meaning for the groundbreaking work of an international group of researchers, led by scientists at Rutgers University-New Brunswick. They have created a synthetic quantum material that cannot be explained using conventional means by mixing two materials that long have been deemed incompatible. The implications of the achievement extend far beyond the lab and have the potential to transform sensor technology and quantum computing.
The achievement itself is at the core of a microscopic “sandwich” composed of several layers of atoms. One of these layers is composed of dysprosium titanate, a material renowned for being a radioactivity trap and for containing elusive magnetic monopoles, particles which have the only qualities of acting like magnets with one end north or south. The second layer is pyrochlore iridate, a magnetic semimetal which is renowned for displaying very unique electronic and magnetic properties in which Weyl fermions reside. These relativistic quasiparticles, predicted by Hermann Weyl in 1929 and first seen in 2015, move at the speed of light and possess odd spin characteristics that render them extremely stable in electronics.
All of these materials individually are “impossible” because they both possess superb quantum characteristics that go against regular physics. However, scientists have been able to integrate them into a homogeneous framework, opening up a new frontier for scientific inquiry. “This work provides a new way to design entirely new artificial two-dimensional quantum materials, with the potential to push quantum technologies and provide deeper insight into their fundamental properties in ways that were previously impossible,” said Rutgers’s Claud Lovelace Endowed Professor of Experimental Physics Jak Chakhalian and principal investigator on the research. Producing this quantum sandwich wasn’t easy.
Scientists spent four years developing an innovative synthesis method and went as far as building a specialized device, the Quantum Phenomena Discovery Platform (Q-DiP), to bring it to life. Funded and finished in 2023, Q-DiP integrates an infrared laser heater with a supplemental laser to allow for atomic-scale layer-by-layer material assembly. The instrument allows scientists to study intricate quantum characteristics at ultra-low temperatures near absolute zero. Chakhalian called the platform “To the best of our knowledge, this probe is unique in the U.S. and represents a breakthrough as an instrumental advance,” The interface the region where the two materials meet is particularly promising for new quantum phenomena to be found.
Dysprosium titanate, or spin ice, contains magnetic moments that are ordered in a water-ice arrangement. The ordering creates magnetic monopoles that appear as a result of interactions in the material. As the director of Max Planck Institute for the Physics of Complex Systems Pyrochlore iridate hosts Weyl fermions, which have electronic properties shielded from interference and impurities and are well optimized for application in next-generation electronics. These fermions are highly sensitive to electromagnetic fields and can transport electricity with otherworldly efficiency. The two materials combined are an environment from which stable and unconventional quantum states can be studied, which is a necessity for the creation of qubits in quantum computers and the advancement of next-generation quantum sensors.
Quantum computing, based on entanglement and superposition effects, has the potential to revolutionize application fields ranging from drug discovery to artificial intelligence.
The novel electronic and magnetic properties of the new material can help to stabilize quantum states, a very significant problem in quantum information science. Chakhalian spoke about the prospect for impact by saying, “This study is a big step forward in material synthesis and could significantly impact the way we create quantum sensors and advances spintronic devices.” Its broader implications are profound. As quantum technology becomes possible, it can transform industries with quicker computations, solid financial and logistics forecasting models, and better machine learning algorithms. Synthesis of dysprosium titanate and pyrochlore iridate isn’t just a scientific marvel; it’s a glimpse of a world where quantum materials transform technology to unprecedented heights.
The journey to this success was marred by significant input from a dedicated group comprising Rutgers students Michael Terilli, Tsung-Chi Wu, and Dorothy Doughty, and material scientist Mikhail Kareev and Ph.D. alumnus Fangdi Wen. Their cumulative effort is a testament to the team work culture of scientific breakthroughs where determination and creativity are the pillars of revolutionary advancements.
While researchers continue to explore this quantum sandwich interface, the possibilities are endless. From controlling the very foundation of quantum interactions to opening doors to revolutionary applications, this breakthrough is a milestone in the quest to unlock the boundless potential of quantum materials. Not only does the research shake our foundations of physics but also inspires a dream of what science is capable of if it tackles the “impossible.”
