‘Quantum Supremacy’ author Dr. Michio Kaku discusses the future of quantum computing on ‘Making Money.’
Category: quantum physics – Page 14
MIT’s quantum tunneling transistors achieve high performance and energy efficiency, surpassing silicon’s limits with nanoengineering.
A new formula that connects a material’s magnetic permeability to spin dynamics has been derived and tested 84 years after the debut of its electric counterpart.
If antiferromagnets, altermagnets, and other emerging quantum materials are to be harnessed for spintronic devices, physicists will need to better understand the spin dynamics in these materials. One possible path forward is to exploit the duality between electric and magnetic dynamics expressed by Maxwell’s equations. From this duality, one could naively expect mirror-like similarities in the behavior of electric and magnetic dipoles. However, a profound difference between the quantized lattice electric excitations—such as phonons—and spin excitations—such as paramagnetic and antiferromagnetic spin resonances and magnons—has now been unveiled in terms of their corresponding contributions to the static electric susceptibility and magnetic permeability. Viktor Rindert of Lund University in Sweden and his collaborators have derived and verified a formula that relates a material’s magnetic permeability to the frequencies of magnetic spin resonances [1].
Scientists have unlocked a new understanding of mesoporous silicon, a nanostructured version of the well-known semiconductor. Unlike standard silicon, its countless tiny pores give it unique electrical and thermal properties, opening up potential applications in biosensors, thermal insulation, photovoltaics, and even quantum computing.
Performing computation using quantum-mechanical phenomena such as superposition and entanglement.
Quantum computers could be made with fewer overall components, thanks to technology inspired by Schrödinger’s cat. A team of researchers from Amazon Web Services has used “bosonic cat qubits,” to improve the ability of quantum computers to correct errors. The demonstration of quantum error correction requiring reduced hardware overheads is reported in a paper published in Nature.
The system uses so-called cat qubits (qubits are the quantum equivalent to classical computing bits), which are designed to be resistant against certain types of noise and errors that might disrupt the output of quantum systems. This approach requires fewer overall components to achieve quantum error correction than other designs.
Quantum computers are prone to errors, which limits their potential to exceed the capabilities of classical computers at certain tasks. Quantum error correction is a method that helps reduce errors by spreading information over multiple qubits, allowing the identification and correction of errors without corrupting the computation. However, most approaches to quantum error correction typically rely on a large number of additional qubits to provide sufficient protection against errors, potentially leading to an overall decrease in efficiency.
Laying the groundwork for quantum communication systems of the future, engineers at Caltech have demonstrated the successful operation of a quantum network of two nodes, each containing multiple quantum bits, or qubits—the fundamental information-storing building blocks of quantum computers.
To achieve this, the researchers developed a new protocol for distributing quantum information in a parallel manner, effectively creating multiple channels for sending data, or multiplexing. The work was accomplished by embedding ytterbium atoms inside crystals and coupling them to optical cavities—nanoscale structures that capture and guide light. This platform has unique properties that make it ideal for using multiple qubits to transmit quantum information-carrying photons in parallel.
“This is the first-ever demonstration of entanglement multiplexing in a quantum network of individual spin qubits,” says Andrei Faraon (BS ‘04), the William L. Valentine Professor of Applied Physics and Electrical Engineering at Caltech. “This method significantly boosts quantum communication rates between nodes, representing a major leap in the field.”
Researchers at the National Graphene Institute at the University of Manchester have achieved a significant milestone in the field of quantum electronics with their latest study on spin injection in graphene. The paper, published recently in Communications Materials, outlines advancements in spintronics and quantum transport.
Spin transport electronics, or spintronics, represents a revolutionary alternative to traditional electronics by utilizing the spin of electrons rather than their charge to transfer and store information. This method promises energy-efficient and high-speed solutions that exceed the limitations of classical computation, for next generation classical and quantum computation.
The Manchester team, led by Dr. Ivan Vera-Marun, has fully encapsulated monolayer graphene in hexagonal boron nitride, an insulating and atomically flat 2D material, to protect its high quality. By engineering the 2D material stack to expose only the edges of graphene, and laying magnetic nanowire electrodes over the stack, they successfully form one-dimensional (1D) contacts.
A new study from the University of Eastern Finland (UEF) explores the behavior of photons, the elementary particles of light, as they encounter boundaries where material properties change rapidly over time. This research uncovers remarkable quantum optical phenomena that may enhance quantum technology and paves the road for an exciting nascent field: four-dimensional quantum optics.
Four-dimensional optics is a research area investigating light scattering from structures which change in time and space. It holds immense promise for advancing microwave and optical technologies by enabling functionalities such as frequency conversion, amplification, polarization engineering and asymmetric scattering. That is why it has captured the interest of many researchers across the globe.
Previous years have seen significant strides in this area. For instance, a 2024 study published in Nature Photonics and also involving UEF highlights how incorporating optical features like resonances can drastically influence the interaction of electromagnetic fields with time-varying two-dimensional structures, opening exotic possibilities to control light.
A team of scientists from Princeton University has measured the energies of electrons in a new class of quantum materials and has found them to follow a fractal pattern. Fractals are self-repeating patterns that occur on different length scales and can be seen in nature in a variety of settings, including snowflakes, ferns, and coastlines.
A quantum version of a fractal pattern, known as “Hofstadter’s butterfly,” has long been predicted, but the new study marks the first time it has been directly observed experimentally in a real material. This research paves the way toward understanding how interactions among electrons, which were left out of the theory originally proposed in 1976, give rise to new features in these quantum fractals.
The study was made possible by a recent breakthrough in materials engineering, which involved stacking and twisting two sheets of carbon atoms to create a pattern of electrons that resembles a common French textile known as a moiré design.
PsiQuantum unveiled Omega, a quantum photonic chipset designed for large-scale quantum computing. This development, detailed in a Nature publication, marks a significant milestone in the mass production of quantum chips. Manufactured in partnership with GlobalFoundries at their Albany, New York facility, Omega integrates advanced components essential for constructing million-qubit quantum computers. The chipset employs photonics technology, manipulating single photons for computations, which offers advantages such as simplified cooling mechanisms. PsiQuantum has achieved manufacturing yields comparable to standard semiconductors, producing millions of these chips. The company plans to establish two Quantum Compute Centers in Brisbane, Australia, and Chicago, Illinois, aiming for operational facilities by 2027. This progress positions PsiQuantum at the forefront of the quantum computing industry, alongside other major companies making significant strides in the field. Summary of the paper in Nature: For decades, scientists have dreamed of building powerful quantum computers using light—photonic quantum computers. These machines could solve complex problems far beyond the reach of today’s most advanced supercomputers. However, a major roadblock has been the sheer difficulty of manufacturing the components required at the necessary scale. Now, researchers have developed a manufacturable platform for photonic quantum computing, marking a significant breakthrough. Their system is built using silicon photonics, a technology that integrates optical components directly onto a chip, much like modern semiconductor chips. The team demonstrated key capabilities: * Ultra-precise qubits: They achieved a stunning 99.98% accuracy in preparing and measuring quantum states. * Reliable quantum interference: Independent photon sources interacted with a visibility of 99.50%, crucial for quantum logic operations. * High-fidelity entanglement: A critical quantum process, known as two-qubit fusion, reached 99.22% accuracy. * Seamless chip-to-chip connections: The team linked quantum chips with 99.72% fidelity, a crucial step for scaling up quantum systems. Looking ahead, the researchers highlight new technologies that will further improve performance, including better photon sources, advanced detectors, and high-speed switches. This work represents a major step toward large-scale, practical quantum computing, bringing us closer to a future where quantum machines tackle problems that are impossible today.
PsiQuantum’s focus is now on wiring these chips together across racks, into increasingly large-scale multi-chip systems – work the company is now expanding through its partnership with the U.S. Department of Energy at SLAC National Accelerator Laboratory in Menlo Park, California as well as a new manufacturing and testing facility in Silicon Valley. While chip-to-chip networking remains a hard research problem for many other approaches, photonic quantum computers have the intrinsic advantage that photonic qubits can be networked using standard telecom optical fiber without any conversion between modalities, and PsiQuantum has already demonstrated high-fidelity quantum interconnects over distances up to 250m.
In 2024, PsiQuantum announced two landmark partnerships with the Australian Federal and Queensland State governments, as well as the State of Illinois and the City of Chicago, to build its first utility-scale quantum computers in Brisbane and Chicago. Recognizing quantum as a sovereign capability, these partnerships underscore the urgency and race towards building million-qubit systems. Later this year, PsiQuantum will break ground on Quantum Compute Centers at both sites, where the first utility-scale, million-qubit systems will be deployed.