Category: quantum physics – Page 276
At the annual IBM Quantum Summit in New York, IBM debuted IBM Quantum Heron, the first in a new series of utility-scale quantum processors with an architecture engineered over the past four years to deliver IBM’s highest performance metrics and lowest error rates of any IBM Quantum processor to date.
IBM also unveiled IBM Quantum System Two, the company’s first modular quantum computer and cornerstone of IBM’s quantum-centric supercomputing architecture. The first IBM Quantum System Two, located in Yorktown Heights, New York, has begun operations with three IBM Heron processors and supporting control electronics.
With this critical foundation now in place, along with other breakthroughs in quantum hardware, theory, and software, the company is extending its IBM Quantum Development Roadmap to 2033 with new targets to significantly advance the quality of gate operations. Doing so would increase the size of quantum circuits able to be run and help to realize the full potential of quantum computing at scale.
DARPA’s Underexplored Systems for Utility-Scale Quantum Computing (US2QC) program seeks to determine whether an underexplored approach to quantum computing can achieve utility-scale operation — meaning its computational value exceeds its cost — faster than conventional predictions.
In the initial phase, each company presented a design concept describing their plans to create a utility-scale quantum computer. In the follow-on phase, selected performers aim to take their concepts to the next level. Now, US2QC’s key goal centers on developing and defending a system design for a fault-tolerant prototype, a smaller-scale quantum computer demonstrating that a utility-scale quantum computer can be constructed as designed and operated as intended.
This prototype system design will identify all required components and sub-systems and establish their minimum performance requirements. A DARPA-led government test and evaluation team consisting of technical experts will evaluate design viability.
Harvard researchers have realized a key milestone in the quest for stable, scalable quantum computing, an ultra-high-speed technology that will enable game-changing advances in a variety of fields, including medicine, science, and finance.
The team, led by Mikhail Lukin, the Joshua and Beth Friedman University Professor in physics and co-director of the Harvard Quantum Initiative, has created the first programmable, logical quantum processor, capable of encoding up to 48 logical qubits, and executing hundreds of logical gate operations, a vast improvement over prior efforts.
Published in Nature, the work was performed in collaboration with Markus Greiner, the George Vasmer Leverett Professor of Physics; colleagues from MIT; and QuEra Computing, a Boston company founded on technology from Harvard labs.
On the pursuit for anyons (Majoranas) in the context of the latest progress on multiple platforms.
Already, the graphene efforts have offered “a breath of fresh air” to the community, Alicea says. “It’s one of the most promising avenues that I’ve seen in a while.” Since leaving Microsoft, Zaletel has shifted his focus to graphene. “It’s clear that this is just where you should do it now,” he says.
But not everyone believes they will have enough control over the free-moving quasiparticles in the graphene system to scale up to an array of qubits—or that they can create big enough gaps to keep out intruders. Manipulating the quarter-charge quasiparticles in graphene is much more complicated than moving the Majoranas at the ends of nanowires, Kouwenhoven says. “It’s super interesting for physics, but for a quantum computer I don’t see it.”
Just across the parking lot from Station Q’s new office, a third kind of Majorana hunt is underway. In an unassuming black building branded Google AI Quantum, past the company rock-climbing wall and surfboard rack, a dozen or so proto–quantum computers dangle from workstations, hidden inside their chandelier-like cooling systems. Their chips contain arrays of dozens of qubits based on a more conventional technology: tiny loops of superconducting wires through which current oscillates between two electrical states. These qubits, like other standard approaches, are beset with errors, but Google researchers are hoping they can marry the Majorana’s innate error protection to their quantum chip.
Absolutely empty – that is how most of us envision the vacuum. Yet, in reality, it is filled with an energetic flickering: the quantum fluctuations. Scientists are currently scientists are gearing up for a laser experiment intended to verify these vacuum fluctuations in a novel way, which could potentially provide clues to new laws in physics.
A research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has developed a series of proposals designed to help conduct the experiment more effectively – thus increasing the chances of success. The team presents its findings in the scientific journal Physical Review D.
The physics world has long been aware that the vacuum is not entirely void but is filled with vacuum fluctuations – an ominous quantum flickering in time and space. Although it cannot be captured directly, its influence can be indirectly observed, for example, through changes in the electromagnetic fields of tiny particles.
Fabrication method could facilitate materials discovery. Harvard team led by Philip Kim innovates in high-temperature superconductors using cuprates. Developed the world’s first superconducting diode, advancing quantum computing.
In a new breakthrough, researchers have used a novel technique to confirm a previously undetected physics phenomenon that could be used to improve data storage in the next generation of computer devices.
Spintronic memories, utilized in advanced computers and satellites, leverage the magnetic states produced by the intrinsic angular momentum of electrons for data storage and retrieval. Depending on its physical motion, an electron’s spin produces a magnetic current. Known as the “spin Hall effect,” this has key applications for magnetic materials across many different fields, ranging from low-power electronics to fundamental quantum mechanics.
More recently, scientists have found that electrons are also capable of generating electricity through a second kind of movement: orbital angular momentum, similar to how Earth revolves around the sun. This is known as the “orbital Hall effect,” said Roland Kawakami, co-author of the study and a professor in physics at The Ohio State University.
In quantum mechanics, particles can exist in multiple states at the same time, defying the logic of everyday experiences. This property, known as quantum superposition, is the basis for emerging quantum technologies that promise to transform computing, communication, and sensing. But quantum superpositions face a significant challenge: quantum decoherence. During this process, the delicate superposition of quantum states breaks down when interacting with its surrounding environment.
To unlock the power of chemistry to build complex molecular architectures for practical quantum applications, scientists need to understand and control quantum decoherence so that they can design molecules with specific quantum coherence properties. Doing so requires knowing how to rationally modify a molecule’s chemical structure to modulate or mitigate quantum decoherence.
To that end, scientists need to know the “spectral density,” the quantity that summarizes how fast the environment moves and how strongly it interacts with the quantum system.
Superconductors have intrigued physicists for decades. But these materials, which allow the perfect, lossless flow of electrons, usually only exhibit this quantum-mechanical peculiarity at temperatures so low—a few degrees above absolute zero—as to render them impractical.
A research team led by Harvard Professor of Physics and Applied Physics Philip Kim has demonstrated a new strategy for making and manipulating a widely studied class of higher-temperature superconductors called cuprates, clearing a path to engineering new, unusual forms of superconductivity in previously unattainable materials.
Using a uniquely low-temperature device fabrication method, Kim and his team report in the journal Science a promising candidate for the world’s first high-temperature, superconducting diode—essentially, a switch that makes current flow in one direction—made out of thin cuprate crystals.