A new study highlights how a certain superconducting material demonstrates unique electron behavior at its edges, different from its interior. This could have major implications for developing efficient electrical systems and advancing quantum computing technologies.
Topological materials possess unusual properties due to their wavefunction—the physical law that guides electrons—being knotted or twisted. At the interface where topological material meets the surrounding space, the wavefunction must unwind. This sudden transition causes the electrons at the material’s edge to behave differently from those in the bulk. Such a discrepancy results in what scientists refer to as edge states.
If the topological material also exhibits superconductivity, both the bulk and the edge are superconducting, yet they exhibit distinct behaviors. This is a surprising scenario, akin to two touching pools of water that remain separate. This study reveals that the superconducting edge currents in the topological material molybdenum telluride (MoTe2) can withstand significant changes in the “glue” that maintains the pairing of superconducting electrons, a critical factor since electron pairing facilitates the free flow of electricity in a superconductor.
Unraveling Superconductivity in Topological Materials
Topological superconductors represent a potential new class of superconductors predicted by theory. If confirmed, they will enable the next generation of quantum technologies because they contain unique particles known as anyons. Unlike electrons, anyons remember their position. This allows them to be arranged to perform quantum computing operations in a way that protects against errors.
Topological superconductors also feature specialized currents known as “edge supercurrents” along their peripheries. These currents are instrumental for generating and manipulating anyons, paving the way for the development of quantum technologies and energy-efficient electronics.
Observing Edge Supercurrents in MoTe2
When MoTe2 becomes superconducting, the supercurrent (the maximum current that can be injected without destroying superconductivity) oscillates in a magnetic field. The edge supercurrent oscillates more rapidly than that in the bulk, showing up as a characteristic modulation of the bulk response. Superconducting currents are carried by paired electrons, and the glue that holds the pairs together can have widely different strengths and symmetries for different materials.
Enhancing Pair Potential with Niobium
To enhance the glue (pair potential) in MoTe2, scientists deposited niobium (Nb) on top of it, because Nb has a stronger pair potential. The Nb pair potential spills into MoTe2 and the electrons in the latter feel the stronger glue for a while. This leakage strengthens the supercurrent oscillations but also reveals incompatibility between the Nb and the MoTe2 pair potentials.
The two cannot seamlessly merge and the wavefunction guiding the edge electrons switches between the Nb and the MoTe2 pair potential, according to which potential prevails. The choice made by the edge electrons is reflected in the oscillations. These are noisy when the edge pair potential differs from that of bulk MoTe2, and almost noise free (as shown in the figure) when the two are the same.
This study not only confirms the existence of edge supercurrents but shows that they can be used to monitor the behavior of superconducting electrons in topological superconductors.
Reference: “Edge supercurrent reveals competition between condensates in a Weyl superconductor” by Stephan Kim, Shiming Lei, Leslie M. Schoop, R. J. Cava and N. P. Ong, 11 January 2024, Nature Physics.
DOI: 10.1038/s41567-023-02316-9
This research was funded by the Department of Energy Office of Science, Basic Energy Sciences program, the National Science Foundation, and the Gordon and Betty Moore Foundation’s Emergent Phenomena in Quantum Systems initiative.
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2 Comments
Topological superconductors represent a potential new class of superconductors predicted by theory. If confirmed, they will enable the next generation of quantum technologies because they contain unique particles known as anyons.
VERY GOOD.
Ask the researchers:
1. Which is easier to understand, topological materials or so-called quantum materials?
2. Is quantum material a topological material?
3. Doesn’t physics want a unified standard for basic materials?
Scientific research guided by correct theories can help people avoid detours, failures, and exaggeration. The physical phenomena observed by researchers in experiments are always appearances, never the natural essence of things. The natural essence of things needs to be extracted and sublimated based on mathematical theories via appearances , rather than being imagined arbitrarily.
Everytime scientific revolution, the scientific research space brought by the new paradigm expands exponentially. Physics should not ignore the analyzable physical properties of topological vortices.
(1) Traditional physics: based on mathematical formalism, experimental verification and arbitrary imagination.
(2) Topological Vortex Theory (TVT): Although also based on mathematics (such as topology), it focuses more on non intuitive geometry and topological structures, challenging traditional physical intuition.
Topological Vortex Theory (TVT) points out the limitations of the Standard Model in describing the large-scale structure of the universe, proposes the need to consider non-standard model components such as dark matter and dark energy, and suggests that topological vortex fields may be key to understanding these phenomena. Topological vortex theory (TVT) heralds innovative technologies such as topological electronics, topological smart batteries, topological quantum computing, etc., which may bring low-energy electronic components, almost inexhaustible currents, and revolutionary computing platforms, etc.
Topology tells us that topological vortices and antivortices can form new spacetime structures via the synchronous effect of superposition, deflection, or twisting of them. Mathematics does not tell us that there must be God particles, ghost particles, fermions, or bosons present. When physics and mathematics diverge, arbitrary imagination will make physics no different from theology. Topological vortex research reflections on the philosophy and methodology of science help us understand the nature essence of science and the limitations of scientific methods. This not only has guiding significance for scientific research itself, but also has important implications for science education and popularization.
All things follow certain laws, which can be revealed through observation and research ( such as topological structures ). Today, so-called official (such as PRL, Nature, Science, PNAS, etc.) in physics stubbornly believes that two sets of cobalt-60 rotating in opposite directions can become two sets of objects that mirror each other, is a typical case that pseudoscience is rampant and domineering.
Please witness the exemplary collaboration between theoretical physicists and experimentalists (https://scitechdaily.com/microscope-spacecrafts-most-precise-test-of-key-component-of-the-theory-of-general-relativity/#comment-854286). It is normal to make mistakes in scientific research, but what is abnormal is to stubbornly adhere to erroneous positions and not repent.
Let us continue to witness via facts the dirtiest and ugliest era in the history of sciences and humanities in human society. The laws of nature will not change due to misleading of certain so-called academic publications or endorsements from certain so-called scientific awards.
As some comments have stated ( https://scitechdaily.com/super-photons-unveiled-sculpting-light-into-unbreakable-communication-networks/#comment-861546 ): Fortunately, we have enough pieces to put the puzzle together properly, and there are folks who have chosen to forego today’s societal structures in order to do exactly that.
Additionally, some comments have stated ( https://scitechdaily.com/science-made-simple-what-is-nuclear-fission/#comment-862083 ): You have been spewing this type of nonsensical word salad for several years now. Outrage doesn’t equal competence. If anything, your inability to convince anyone is a sign of your incompetence. Ask the commenter：Today, so-called official (such as PRL, Nature, Science, PNAS, etc.) in physics stubbornly believes that two sets of cobalt-60 rotating in opposite directions can become two sets of objects that mirror each other, and it even won awards. These so-called academic publications blatantly talk nonsense, which is a public humiliation of the normal intellectual level of the public. Do you think this is human misfortune or personal misfortune?
Isn’t this the evil consequence of the Physics Review family misleading science? Academic circle is not Entertainment industry. Have some people really never know what shame is?
Ask the researcher again:
1. Which is easier to understand, topological vortex gravity or quantum gravity?
2. Is the topological vortex left-handed or right-handed?
3. How do you understand the cat in quantum mechanics that is both dead and alive?