New quantum technologies developed by the Quantum Systems Accelerator (QSA) are driving novel scientific discoveries in physics, giving scientists advanced tools to explore complex behaviors of interacting quantum particles and the physical properties of materials. QSA, a National Quantum Information Science Research Center led by Lawrence Berkeley National Laboratory (Berkeley Lab) and funded by the U.S. Department of Energy, conducts research that fuels the development of quantum-enabled materials and technologies, leveraging quantum information science to accelerate the discovery and design of advanced materials for energy applications. QSA scientists from 15 different institutions are collaborating to advance materials physics and build the future of fundamental scientific discovery as the scientific community builds on powerful classical computers and enters the quantum realm for processing information better and faster.

QSA scientists have advanced major quantum computing technologies based on superconducting qubits, trapped ions, and neutral atoms.  These different technologies can be applied in quantum science to study fundamental phenomena and advance new materials. The scientific and technological progress in materials physics led by QSA facilitates the understanding and design of novel properties in superconductors, quantum spin liquids, magnetism, and topological materials.

Simulating Materials with Neutral Atoms

Atom arrays, structured arrangements of atoms used to create a controlled and reproducible quantum system, are tools that QSA scientists have employed to deepen understanding and contribute to developing advanced quantum technologies.

In a recent QSA study using neutral atom technology, QSA researchers employed specialized simulation methods to investigate the dynamic behavior of superconductors under non-equilibrium conditions, such as time-dependent external fields or varying interaction strengths. Their findings, published in a Nature paper, revealed previously unobserved phenomena in superconductors when driven out of equilibrium. This understanding of dynamic phases can potentially improve superconductor performance, essential for applications such as MRI machines and maglev trains. It could even contribute to the development of lossless power grids. Enhanced superconductors could lead to more efficient and widely adopted technologies.

 “Using quantum simulation techniques really allowed us for the first time to look closely at these important phases of the superconductor, which in turn will help us make better and more efficient superconducting systems,” said James K.Thompson, a scientist who led the study in collaboration with theorist Ana Maria Rey.

QSA scientists looked at how a programmable quantum simulator could be used to study different quantum phases of matter, furthering understanding exotic states of matter for the first time and studying magnetism at the quantum level. Their findings help explain the physics underlying materials’ properties and could be used to engineer the materials of the future. The research, published in a recent Nature paper, used a quantum simulator with 256 atoms to study different quantum phases of matter with distinct configurations in which matter can exist when sizes and temperatures are controlled. By moving the atoms into shapes such as squares, honeycombs, and triangles, QSA scientists manipulated how the qubits would interact with one another and made important measurements of quantum phases of matter and quantum spin liquids. Understanding these quantum phases is crucial for developing quantum technologies—the ability to manipulate and observe these phases gives scientists tools to create more advanced quantum computers and materials with unique properties that are useful in various high-tech applications.

“The unprecedented size, coherence, and programmability of quantum simulators based on neutral atom arrays enabled the observation of long-sought quantum phases and quantum phase transitions. These breakthroughs could pave the way for designing and manufacturing materials with exotic properties.” said study author Sepehr Ebad.

QSA scientists also deployed the quantum simulator to investigate dipolar quantum solids, materials where particles interact through their dipole moments (a measure of their electrical polarity). Their findings, published in a Nature paper, further the understanding of new states of matter and their potential applications in quantum computing and materials science. This research could lead to the creation of new materials with special properties and more robust quantum systems.

“This research demonstrates that long-range dipolar interactions in optical lattices can lead to novel strongly-correlated quantum phases, unlocking new avenues for quantum simulations and enhancing the programmability of quantum systems—key for quantum computing. It also deepens our understanding of highly entangled states of matter, paving the way for advanced materials and more robust quantum systems,” said Lin Su, a researcher from Harvard who co-authored the study.

Trapped Ions as Materials Simulators

Turning to trapped ion technology, QSA scientists recently used a programmable quantum simulator to observe different phases of topological insulators and gain new insights into the non-equilibrium dynamics of topological states of matter. Topological insulators are materials with unique surface or edge properties that do not extend to their bulk.  These materials hold promise for advancing electronic and magnetic devices, sensing technologies, and quantum computing. Published on the arXiv, the study sheds light on the magnetic properties of topological materials that are out of equilibrium. The QSA researchers engineered the topological properties of a trapped-ion crystal using laser fields and studied magnetic phenomena not previously observed in other materials. In particular,  they showed how the edges of a crystal can maintain its magnetization through topological protection despite the bulk being unmagnetized.  Unlike general-purpose quantum computers, quantum simulators are specialized for understanding specific quantum phenomena, such as the subtle quantum effects and behaviors that are challenging to detect in physical materials.

Additional QSA-funded research published in Nature Physics, used trapped ion technology in a one-dimensional quantum simulator to enable observations of phase transitions at non-zero energy density. Understanding these phase transitions is important for applying quantum computers to predict material properties, which often must be used at higher temperatures. In the study, scientists used a quantum simulator to explore these phenomena in a one-dimensional system, in which such a phase transition had been predicted for 50 years but had never been observed. They found that as they tuned the energy density, the system underwent a phase transition at finite energies. This showcases the power of quantum simulators to probe phenomena that have eluded observation for decades.  

“These insights could lead to advances in predicting properties of materials with quantum computers,” said study author Alexander Schuckert.

Superconducting Qubits Model Materials Physics Processes

QSA scientists are also working on superconducting circuits, another promising qubit technology. In a recent paper published in Nature Physics, a team of QSA researchers engineered a two-dimensional qubit array that mimicked the effects of a magnetic field. Using a technique known as “synthetic gauge fields,” the researchers successfully introduced an artificial vector potential into the system, a critical ingredient for controlling qubit dynamics in quantum circuits.

The significance of the synthetic magnetic field induced by the vector potential lies in its ability to enable quantum emulations of many-body physics in extreme magnetic fields. For example, in materials, electrons “originate” from atomic orbitals. When two atoms are close, their orbitals overlap, and electrons can “hop” from one atom to another. In the presence of a magnetic field, that hopping behavior becomes more complex. On a superconducting quantum computer, microwave photons hopping between qubits are used to mimic electrons hopping between atoms. But, because photons are not charged particles like electrons, the photons’ hopping behavior would remain the same in a physical magnetic field. Using a synthetic magnetic field, the authors could emulate the dynamics of electrons in condensed matter systems on their superconducting processor. 

Another preprint featuring QSA research demonstrated a superconducting qubit array emulating the phenomenon of flat-band (de)localization. This work showed how superconducting circuits can mimic complex quantum behaviors previously considered exclusive to more exotic materials.

Flat-band systems – where electronic states feature zero velocity – generally are associated with a rich set of features because the quenched kinetic energy magnifies particle interactions. Being able to create and study flat-band systems in superconducting qubit arrays leverages the ability to generate synthetic magnetic fields in these systems.

In such flat-band systems, electrons become localized due to the increased interaction with their neighbors. Increasing the disorder in the flat bands tends to lessen this localization. This is contrary, however, to the well-studied Anderson localization, where increasing disorder should lead to localization. In effect, what the authors have emulated is “disorder-induced delocalization.”

“By using synthetic magnetic fields, we could create a flat-band system that exhibits increasing delocalization with increased disorder, a counterintuitive consequence of flat-band physics,” said study author Ilan Rosen.

This demonstration is indicative of a future where we can engineer qubit systems that emulate the behavior of materials or chemistries without the need to create them directly. Ultimately, this experiment isn’t just about showing off the latest quantum tricks—it’s about making the impossible possible and setting the stage for the next generation of quantum technologies.

QSA brings together a collaborative team of experts from national laboratories, universities, and industries to accelerate the development of quantum technologies. Together, they are conducting research and building systems beyond today’s state-of-the-art quantum computers to accelerate scientific discovery across disciplines.  

“At QSA, we have advanced quantum technologies to study exciting science challenges in many-body systems and materials physics. QSA plays a critical role in supporting the missions of the DOE’s Advanced Scientific Computing Research (ASCR) program and collaborates with other national science offices by fostering breakthroughs in scientific discovery and technological innovation,” said Bert de Jong, QSA director.