Insider Brief:
- Materials science is integral to the development of quantum computing, providing insights that can lead to qubit stability, control, and performance by understanding unique material properties for precise quantum state management.
- Researchers at Argonne National Laboratory and Northern Illinois University are advancing quantum computing by using neodymium to stabilize light-controlled electron spins in perovskite materials, potentially improving qubit coherence and reliability.
- A Rice University study reveals that kagome lattice materials, specifically iron-tin thin films, gain magnetic properties from localized rather than immobile electrons, challenging existing theories and offering new possibilities for applications of quantum logic.
- At the University of Sherbrooke, scientists have developed a theoretical framework to address qubit readout issues in superconducting quantum systems, potentially leading to improved readout fidelity and reduced error correction in quantum devices.
A review of quantum computing roadmaps from major industry players reveals a clear trend: many are betting on chemistry and materials science as the first fields that can demonstrate the quantum edge. This emphasis is not surprising; unlike many fields where quantum computing is explored for the potential for speed compared to classical methods, these disciplines are grounded in quantum mechanics, making them uniquely suited to take advantage of quantum computing. However, the relationship is more than simply beneficial – it is essentially symbiotic. Materials science has become integral to informing quantum computing through new insights that improve qubit development and computational reliability. With quantum computing relying on materials capable of precise control over quantum states, researchers are finding innovative ways to rely on unique material properties that enhance qubit performance.
Light-Controlled Rotations in Perovskites for Qub Enhancement
Recent research from Argonne National Laboratory and Northern Illinois University has shown how light-manipulated electron spins in perovskite materials, specifically, methylammonium lead iodide (MAPbI3), can advance quantum computing technology. Perovskites, the materials traditionally used in solar cells, exhibit a promising structure for quantum applications due to their ability to host stable spin states. In quantum computing, spin – a fundamental property of particles such as electrons – is essential as it can represent quantum states, such as “up” and “down”, allowing qubits to encode information in superpositions.
To extend the exciton lifetime within MAPbI3, the researchers introduced neodymium, a rare earth metal with unpaired electrons. According to Argonne physicist Saw Wai Hla, “By modifying the concentration of neodymium in the concentration of excitons, we can end up using neodymium as a kind of probe for the spins in the exciton,” enabling extended quantum coherence. This interaction creates a spin-entangled state, effectively binding the exciton electrons to those of the neodymium, which improves the stability of the material and allows precise control of the qubit states, potentially leading to more reliable quantum devices.
Kagome Lattice: Exploring Quantum Magnetism for Enhanced Computing
How does basket weaving relate to materials for quantum computing? In more ways than expected. A recent discovery by physicists at Rice University and collaborators explores the magnetic and electronic behaviors of kagome lattice materials, specifically iron-tin (FeSn) thin films. This research, published in Nature Communications, is directly relevant to superconducting quantum computers and high-temperature superconductors by reshaping our understanding of how magnetism and electronic interactions work in these advanced materials. Kagome lattices, structured in a distinctive mesh-like pattern reminiscent of woven baskets, are known for their ability to support quantum phases such as topological flat bands—quantum states that preserve electronic configurations without energy loss.
The team’s study reveals that the magnetic properties of FeSn actually come from localized electrons rather than the mobile electrons traditionally believed to drive magnetism in kagome metals. This challenges old theories and suggests a more complex relationship between magnetism and electron behavior in these materials. As Ming Yi, an associate professor at Rice, noted, “This work is expected to stimulate further experimental and theoretical studies on the emergent properties of quantum materials, deepening our understanding of these enigmatic materials and their potential real-world applications. .”
The implications of this research extend beyond FeSn, as understanding the flat bands and electron correlations in kagome magnets could impact future technologies in areas such as high-temperature superconductivity and topological quantum computing. By examining how magnetism and flat bands interact to produce quantum states, the team’s findings point to potential applications in quantum logic gates and other elements of quantum computing architectures.
Chirality in Nanomaterials: A New Window on Quantum Properties
Chirality, the property that makes objects non-superimposable to their mirror image, has traditionally been observed in organic molecules, but is gaining attention in nanomaterials for quantum applications. Researchers from the University of Camerino, the University of South Africa and the University of Texas at Austin have recently pointed out that chiral nanomaterials exhibit unique spin-polarized electron transport, which may have implications for spintronics and quantum information technologies. This chirality-induced spin selectivity can be used to control quantum spin states with high precision.
For example, spintronic devices—components also used in quantum computing that rely on spin rather than charge—can use chiral nanostructures to maintain coherence over longer periods of time, addressing a common challenge in quantum computing.
Addressing Qubit reading challenges with superconducting materials
While the previously discussed materials studies were primarily centered around deepening the understanding of material properties, a recent theoretical advance by scientists at the University of Sherbrooke has taken a more application-focused approach, aiming for an ongoing challenge in superconducting qubit readouts. Superconducting qubits, which are widely praised for their high efficiency, have struggled with accurate readouts due to a phenomenon where qubits can escape their target quantum states during measurement. This issue, according to the study, arises when the microwave signals used in the readouts inadvertently excite the qubits into higher, unwanted energy states, a process called “transmon ionization.”
The team developed a comprehensive theoretical framework to explain and predict this ionization, revealing that qubits in transmon-based systems can be driven into unintended states due to multiphoton resonances within the system’s energy levels. According to the research, these multiphoton resonances occur at specific photon number thresholds, causing state transitions that interfere with the non-destructive nature expected from qubit measurements in quantum circuit electrodynamics configurations. By identifying these thresholds, the researchers have provided a basis for tuning readout parameters, which can improve measurement fidelity in superconducting qubits and potentially reduce reliance on extensive error-correction protocols.
Mutual Progress: Materials as a Catalyst
The evolution of scientific discovery is often piecemeal—repetitions in one place gradually build momentum in another, an ever-continuing symbiosis. While quantum computing for materials science has been actively explored, materials science remains a necessary catalyst for informing the development of quantum computing. From the manipulation of spin states in perovskites to the development of stable qubits in kagome lattices, each discovery sheds light on the value of material properties tailored to quantum demands.