Spanish Physicist Discovers ‘Inverse Philosopher's Stone'
For centuries, medieval alchemists sought the elusive philosopher's stone, a mythical substance believed to transform base metals into gold. Spanish physicist Pablo Jarillo Herrero is now in the running for a Nobel Prize, having discovered something akin to that myth: what he calls an “inverse philosopher's stone.” This new material does not transmute ordinary substances into treasures, but instead, it possesses the remarkable ability to “become all things,” according to Jarillo Herrero.
The Science Behind Graphene
Born in Valencia 49 years ago, Jarillo Herrero explains that by applying adhesive tape to graphite—the primary component of pencil leads—one can create an astonishing ultrathin material: graphene. This single-atom-thick layer of carbon has captured the attention of researchers worldwide. In 2011, Canadian physicist Allan MacDonald predicted that if two layers of graphene were superimposed and slightly rotated at a “magic angle” of 1.1 degrees, unexpected electronic properties would emerge. In 2017, Jarillo Herrero's team at the Massachusetts Institute of Technology (MIT) achieved what MacDonald deemed “almost science fiction,” securing the elusive inverse philosopher's stone. Both were awarded the FundaciĂ³n BBVA's Frontiers of Knowledge Prize in Basic Sciences in January, which includes a €400,000 cash prize, and the prestigious Wolf Prize in Physics in 2020.
Pioneering Twistronics
Jarillo Herrero has launched a new field within physics known as twistronics, studying the properties that arise when ultrathin layers of various materials are twisted together. When two layers of graphene are rotated by the magic angle, they can act as a superconductor, allowing electricity to flow without resistance. By adding more layers or changing configurations, additional properties such as magnetism, insulation, and even ferroelectricity emerge, proving ideal for developing more efficient supercomputers and enhancing artificial intelligence.
In his lab, Jarillo Herrero does not only work with graphene but also experiments with other nanomaterials such as transition metal dichalcogenides, which can exhibit similar properties when twisted and may eventually replace silicon, the cornerstone of modern electronics. While he expresses a desire to win a Nobel Prize, he emphasizes that it is not a driving concern.
The Concept of an Inverse Philosopher's Stone
Question: What is an inverse philosopher's stone?
Answer: In the Middle Ages, the philosopher's stone was sought as a means to transmute materials into gold. When I explain that magic-angle graphene can produce many phases of matter, some liken this to the philosopher's stone. It shares a spirit of transformation; however, it is actually the reverse. We use a single material to derive various properties like magnetism, ferroelectricity, superconductivity, and insulators. Rather than finding a substance that turns everything into gold, we have discovered one that can transform into many different things.
Practical Applications and Future Potential
Question: What can you create with just a pencil and adhesive tape?
Answer: We literally use a crystal of graphite, similar to a pencil lead, and adhesive tape to produce magic-angle graphene and experiment with its various properties.
Question: Can you turn pencil graphite into a magnet?
Answer: Yes, graphite can be transformed into a magnet or superconductor at very low temperatures, even without twisting it.
Question: Who coined the term “twistronics”?
Answer: Officially, my colleague from Harvard, Tim Kaxiras, was the first to write it down in a 2017 study. Unofficially, we were discussing ideas when I suggested calling it “twistronics” to signify making electronics with twists. I think he might have remembered it and used it in their publication.
Challenges in Twistronics Research
Question: When MacDonald labeled your work as “almost science fiction,” why was it so challenging?
Answer: MacDonald and his team predicted an alteration in graphene's electronic properties at the magic angle, but they were unaware it could behave as a superconductor or insulator. Our 2018 publication shocked everyone; the field exploded afterward. The challenge added to the complexity of meticulously stacking a single-atom-thick material at the precise angle of 1.1 degrees, which took us eight years of dedicated research. Achieving the necessary layer separation with exceptional precision is where the real difficulty lies.
Question: Is the term “moirĂ©” related to the moirĂ© effect?
Answer: Exactly! In mathematics, it's well-known that rotating two periodic structures creates a superstructure, resulting in a moiré pattern.
Looking Ahead: The Future of Technology
Question: How do you envision the future of twistronics technology in 10 to 20 years?
Answer: To me, that's a short time frame. I like to think about 30 or 40 years. Although we have this inverse philosopher's stone, it is not currently practical because we don't know how to mass-produce identical devices. Ideally, in the next couple of decades, the technology will evolve to enable large-scale twistronics applications for magnets, ferroelectric materials, superconductors, etc., using just a few materials and tweaking configurations. While we can achieve much now, none of it works at room temperature. Nevertheless, some applications, like quantum computers, currently use aluminum as a superconductor, requiring extreme cooling. Twistronic materials could revolutionize these applications and make them significantly more powerful if we can produce them on a large scale.
Research Environment in Spain vs. the MIT
Question: Have you received appealing offers to return to Spain, such as establishing a National Center for Twistronics in Valencia?
Answer: Not really. While I've been approached multiple times, I haven't received an offer that would make me consider returning. Any proposal would have to include research and personal conditions similar to what I have at MIT—salary, flexibility, etc. The current Spanish system, both public and private, does not allow for this. MIT is a private institution with substantial public funding for research.
Question: What do you mean by that?
Answer: People understand that achieving excellence in football requires hiring the best, providing competitive salaries and training conditions. However, this mindset doesn't always extend to the scientific realm. Europe, particularly Spain, needs to prioritize technological independence, especially given the increasing global competition.
The Importance of Meritocracy in Science
Question: You are among the few Spanish scientists with a chance to win a Nobel Prize.
Answer: I suppose so. I am receiving awards that previous Nobel laureates have also received. While I'd be honored, it doesn't consume my thoughts. There are a few Spaniards in line for these prestigious international awards, and I happen to be one of them. If Spain wants more Nobel laureates, it's simple: invest in young talent, embrace meritocracy, and strive for intellectual ambition, similar to football or culinary success. It involves providing resources and attracting international talent.
Question: Why is that difficult to achieve?
Answer: Few institutions genuinely practice a radical meritocracy. At MIT, it's unthinkable not to hire the best candidate. The contrast becomes apparent when you have to evaluate a colleague for a position. A straightforward dismissal for a candidate who is good but not exceptional can be uncomfortable.
Question: That sounds challenging.
Answer: It is precisely like managing a sports team. If a player is not up to par, they must be replaced. Many countries inquire how to establish an institution like MIT. When I disclose the necessary resources, most are apprehensive. Yet, some countries are willing to commit. However, I emphasize that adequate resources are just part of the equation; recruiting and developing human capital is far more complex. During my visits to Spain, I often encounter laboratories equipped similarly to mine but lacking the talented workforce we have at MIT. Although MIT is relatively small, it produces more patents than all Spanish universities combined due to the quality of its human capital.
In summary, the scientific and technological impact of MIT likely surpasses that of all 100 Spanish universities combined.
