Excitons are drawing attention as possible quantum bits (qubits) in tomorrow's quantum computers and are central to optoelectronics and energy-harvesting processes. However, these charge-neutral quasiparticles, which exist in semiconductors and other materials, are notoriously difficult to confine and manipulate.
Now, for the first time, researchers have created and directly observed highly localized excitons confined in simple stacks of atomically thin materials. The work confirms theoretical predictions and opens new avenues for controlling excitons with custom-built materials.
"The idea that you can localize excitons on specific lattice sites by simply stacking these 2D materials is exciting because it has a variety of applications, from designer optoelectronic devices to materials for quantum information science," said Archana Raja, co-lead of the project and a staff scientist at Lawrence Berkeley National Laboratory's (Berkeley Lab) Molecular Foundry, whose group led the device fabrication and optical spectroscopy characterization.
Re: Quantum Computing News and Discussions
Posted: Wed Feb 08, 2023 7:11 pm
by weatheriscool
Quantum breakthrough could revolutionise computing
Scientists have come a step closer to making multi-tasking 'quantum' computers, far more powerful than even today's most advanced supercomputers.
Quantum computers make use of the weird qualities of sub-atomic particles.
So-called quantum particles can be in two places at the same time and also strangely connected even though they are millions of miles apart.
A Sussex University team transferred quantum information between computer chips at record speeds and accuracy.
AI & Quantum Computing are the two pillars on which we will reach longevity escape velocity.
When we're able to simulate chemical reactions more accurately using quantum computers hopefully this will lead to an explosion in successful drug discovery as opposed to todays incredibly hit and miss trial and error processes.
A new form of heterostructure of layered two-dimensional (2D) materials may enable quantum computing to overcome key barriers to its widespread application, according to an international team of researchers.
The researchers were led by a team that is part of the Penn State Center for Nanoscale Science (CNS), one of 19 Materials Research Science and Engineering Centers (MRSEC) in the United States funded by the National Science Foundation. Their work was published Feb. 13 in Nature Materials.
A regular computer consists of billions of transistors, known as bits, and are governed by binary code ("0" = off and "1" = on). A quantum bit, also known as a qubit, is based on quantum mechanics and can be both a "0" and a "1" at the same time. This is known as superposition and can enable quantum computers to be more powerful than the regular, classical computers.
There is, however, an issue with building a quantum computer.
"IBM, Google, and others are trying to make and scale up quantum computers based upon superconducting qubits," said Jun Zhu, Penn State professor of physics and corresponding author of the study. "How to minimize the negative effect of a classical environment, which causes error in the operation of a quantum computer, is a key problem in quantum computing."
"We are building a network of quantum computers, which use trapped ions to store and process quantum information," Peter Drmota, one of the researchers who carried out the study, told Phys.org. "To connect quantum processing devices, we use single photons emitted from a single atomic ion and utilize quantum entanglement between this ion and the photons."
In a demonstration that promises to help scale up quantum computers based on tiny dots of silicon, RIKEN physicists have succeeded in connecting two qubits—the basic unit for quantum information—that are physically distant from one another.
Many big IT players—including the likes of IBM, Google and Microsoft—are racing to develop quantum computers, some of which have already demonstrated the ability to greatly outperform conventional computers for certain types of calculations. But one of the greatest challenges to developing commercially viable quantum computers is the ability to scale them up from a hundred or so qubits to millions of qubits.
In terms of technologies, one of the front-runners to achieve large-scale quantum computing is silicon quantum dots that are a few tens of nanometers in diameter. A key advantage is that they can be fabricated using existing silicon fabrication technology. But one hurdle is that, while it is straightforward to connect two quantum dots that are next to each other, it has proved difficult to link quantum dots that are far from each other.
IBM wants to scale up its quantum computers to over 4,000 qubits by 2025 — but we’re not quite there yet. For now, we have to make do with significantly smaller systems and today, IBM announced the launch of its Osprey quantum processor, which features 433 qubits, up from the 127 qubits of its 2021 Eagle processor. And with that, the slow but steady march toward a quantum processor with real-world applications continues.
“The new 433 qubit ‘Osprey’ processor brings us a step closer to the point where quantum computers will be used to tackle previously unsolvable problems,” said Darío Gil, senior vice president, IBM and director of Research. “We are continuously scaling up and advancing our quantum technology across hardware, software and classical integration to meet the biggest challenges of our time, in conjunction with our partners and clients worldwide. This work will prove foundational for the coming era of quantum-centric supercomputing.”
Telecom minister Ashwini Vaishnaw on Monday said the country's first quantum computing-based telecom network link is now operational in the national capital. While speaking at the first international quantum enclave, Vaishnaw said that the quantum communication link is now operational between Sanchar Bhawan and National Informatics Centre office located in CGO Complex in the national capital.
"The first quantum secure communication link between Sanchar Bhawan and NIC, CGO complex is now operational," Vaishnaw said and announced a Rs 10 lakh prize money for ethical hackers who can break the encryption of the system.
"We are also launching a hackathon, a challenge round, for anybody who breaks this system and system developed by C-DoT, we will be giving Rs 10 lakh per break," Vaishnaw said.
The minister inaugurated a small exhibition of quantum computing firms and invited them to run pilot projects for communications networks and Indian Railways.
More companies are starting to consider the impact that quantum computing will have on their business in the coming years. According to a survey by Deloitte, about half of all companies believe that they are vulnerable to a “harvest now, decrypt later” attack, where encrypted information is stored until a future quantum computer can decrypt the data. No wonder, then, that 61% of firms have either conducted an assessment of their readiness or plan to analyze the issue within five years.
In 2022, the National Institute of Standards and Technology (NIST) made a significant decision to help companies prepare for a world where quantum computing is commonplace. The decision was also an effort to help protect today’s data from tomorrow’s quantum computers. The U.S. technology agency selected four algorithms for encryption methods to replace public key infrastructure (PKI) algorithms currently in use as a way of protecting data encrypted today against quantum computers developed in the future.