Anyons in Two Dimensions: The Secret to Persistent Superconductivity Amid Magnetism

The field of condensed matter physics has long been a fertile ground for discoveries that challenge our understanding of the quantum world. Among these phenomena, superconductivity and magnetism have historically been considered mutually exclusive, each demanding a delicate balance of electron behavior that precludes the other.

However, recent breakthroughs suggest a radical paradigm shift is underway, rooted in the behavior of quasiparticles known as anyons. Theoretical physicists at MIT propose that these exotic entities could underpin a new form of superconductivity capable of coexisting with magnetism, potentially opening the door to revolutionary advances in quantum computing and material science.

The Long-Standing Paradox: Superconductivity vs. Magnetism

Superconductivity and magnetism are emergent macroscopic quantum states, arising from the collective behavior of electrons within materials. Superconductivity occurs when electrons pair into Cooper pairs and flow without resistance, allowing electrical currents to traverse a lattice without energy loss. In contrast, magnetism arises when the electrons’ spins align, generating a macroscopic magnetic field.

Historically, the two states have been seen as incompatible. Magnetic fields disrupt Cooper pairs, breaking the superconductive state. This apparent mutual exclusivity has constrained material scientists, limiting the potential for devices that require simultaneous superconducting and magnetic properties. Yet, two recent experiments have upended this assumption:

• Rhombohedral Graphene: MIT physicist Long Ju and colleagues discovered simultaneous superconductivity and magnetism in a synthesized graphene material composed of four or five layers.

• Molybdenum Ditelluride (MoTe2): Independent research identified similar coexistence in MoTe2, a semiconducting crystal exhibiting a fractional quantum anomalous Hall effect (FQAH), which fractionalizes electrons into quasiparticles.

These findings demand a theoretical explanation capable of reconciling the duality of these states.

Introducing Anyons: The Third Particle Type

Traditional particle physics classifies particles into bosons and fermions. Bosons, such as photons, are sociable, traveling in packs and enabling phenomena like Bose-Einstein condensates. Fermions, including electrons, protons, and neutrons, are more solitary, obeying the Pauli exclusion principle that prevents them from occupying identical states.

Anyons, in contrast, exist exclusively in two-dimensional systems and exhibit behavior that is neither strictly bosonic nor fermionic. First predicted in the 1980s, the term "anyon" was coined by MIT physicist Frank Wilczek to convey the idea that "anything goes" regarding their quantum statistics. These quasiparticles arise when electrons fractionalize in two-dimensional materials under specific conditions, often linked to exotic quantum phenomena such as the FQAH effect observed in MoTe2.

Theoretical Framework: Superconducting Anyons

Senthil Todadri and Zhengyan Darius Shi, theoretical physicists at MIT, have proposed that anyons can form superconducting states in materials where traditional superconductivity would fail due to magnetism. Their research, published in the Proceedings of the National Academy of Sciences, outlines the conditions under which anyons can overcome intrinsic frustration and collectively move without resistance.

• Frustration Phenomenon: Anyons are naturally resistant to movement due to long-range quantum interactions. Todadri explains, "Each anyon may try to move, but it’s frustrated by the presence of other anyons, even at large distances."

• Fractional Charges: MoTe2 allows electrons to split into anyons with either one-third or two-thirds of the electron charge. When two-thirds-flavor anyons dominate, they can pair and flow collectively, forming a supercurrent akin to Cooper pairs in conventional superconductors.

• Swirling Supercurrents: Upon formation, superconducting anyons generate novel swirling supercurrents that appear spontaneously in random regions of the material, a phenomenon distinct from traditional superconductivity.

Implications for Quantum Computing

The realization of superconducting anyons has profound implications for quantum technology. Anyons could serve as the foundation for stable qubits, the fundamental units of quantum information. Unlike conventional qubits, which are susceptible to decoherence and environmental noise, anyon-based qubits leverage topological properties to maintain coherence over extended timescales. This topological protection arises because information is encoded in the collective state of multiple anyons, making it resilient to local disturbances.

• Fault-Tolerant Qubits: By harnessing anyonic states, researchers could design qubits that are inherently fault-tolerant, reducing error rates in quantum computations.

• Complex Quantum Gates: The braiding of anyons—a process in which quasiparticles are moved around one another—can implement complex quantum logic operations, enabling scalable quantum architectures.

• Enhanced Computational Efficiency: Anyonic qubits offer potential for processing capabilities far beyond classical bits, promising breakthroughs in cryptography, materials modeling, and optimization problems.

Experimental Verification and Challenges

While the theoretical framework is compelling, experimental confirmation remains crucial. Physicists must observe and manipulate superconducting anyons directly in controlled laboratory settings. Key challenges include:

1. Material Synthesis: Creating two-dimensional materials with precise electron densities to favor two-thirds-flavor anyons.

2. Measurement Precision: Detecting the subtle supercurrents produced by anyons, which differ from conventional superconducting signals.

3. Quantum Control: Developing techniques to braid anyons reliably for quantum computation experiments.

Todadri notes,

"Many more experiments are needed before one can declare victory, but this theory is very promising and shows that there can be new ways in which the phenomenon of superconductivity can arise."

Broader Impacts on Condensed Matter Physics

The discovery of superconducting anyons could redefine several paradigms in condensed matter physics:

• Anyonic Quantum Matter: A new class of quantum materials characterized by collective anyon behavior and emergent topological phenomena.

• Coexistence of Conflicting States: A framework for understanding how traditionally incompatible macroscopic states can exist simultaneously in two-dimensional systems.

• Material Design Principles: Guidelines for engineering materials with tailored electron densities and topological properties to achieve novel quantum states.

Comparison of Particle Types and Quantum States

Property	Bosons	Fermions	Anyons
Space Dimensionality	3D	3D	2D
Behavior	Pack together	Avoid each other	Fractional statistics, flexible
Examples	Photon	Electron, Proton, Neutron	Fractionalized electron states in MoTe2
Role in Superconductivity	Forms Cooper pairs indirectly	Forms Cooper pairs	Forms collective supercurrent under certain fractions

Future Directions and Research Opportunities

Researchers at MIT are continuing to explore the theoretical and practical potential of anyons. Potential avenues include:

• Engineering Topological Superconductors: Materials designed to exploit anyonic states for quantum device applications.

• Cross-Disciplinary Applications: Insights from anyonic physics could inform photonics, spintronics, and neuromorphic computing.

• Macroscopic Quantum Phenomena: Investigating how microscopic anyon interactions can manifest as large-scale superconducting behaviors.

Dr. Robert Laughlin, Nobel laureate and pioneer in fractional quantum Hall physics, underscores the significance:

"The discovery of superconducting anyons, if verified experimentally, would represent a fundamental shift in how we understand electron interactions in condensed matter systems."

Conclusion

The emergence of anyons as a potential mechanism for superconductivity in the presence of magnetism challenges decades of assumptions in quantum physics. By fractionalizing electrons into quasiparticles capable of collective, frictionless flow, researchers are not only expanding the boundaries of condensed matter physics but also laying the groundwork for a new era in quantum technology. The concept of anyonic quantum matter could redefine the future of materials science and quantum computation, offering avenues for fault-tolerant qubits, exotic superconducting states, and applications previously thought impossible.

As this research evolves, institutions such as MIT continue to drive the frontier of quantum physics, providing theoretical and experimental frameworks that may soon translate into practical technologies. The work of Todadri, Shi, and their colleagues represents a pivotal step toward understanding the complex interplay between particle fractionalization, superconductivity, and magnetism.

Further Reading / External References

1. Jennifer Chu, MIT News, "Anything-goes 'anyons' may be at the root of surprising quantum experiments," December 22, 2025. Link

2. Jennifer Chu, Phys.org, "Anything-goes 'anyons' may be at the root of surprising quantum experiments," December 22, 2025. Link

3. Zhengyan Darius Shi et al., "Anyon delocalization transitions out of a disordered fractional quantum anomalous Hall insulator," Proceedings of the National Academy of Sciences, 2025. DOI: 10.1073/pnas.2520608122