What if time didn’t just move forward? Scientists have uncovered something astonishing in a recent quantum physics experiment — the existence of ‘negative time.’ This mind-bending discovery defies conventional logic, suggesting that particles may not follow the rules we thought were unbreakable.
In a monumental stride toward the realization of practical quantum computing and advanced quantum networks, researchers at the prestigious Cavendish Laboratory of the University of Cambridge have successfully crafted a fully operational quantum register utilizing the atomic properties within a semiconductor quantum dot. This innovative development could pave the way for pivotal advancements in quantum information technology, crucial for the anticipated future where quantum networking integrates into everyday digital communications.
This breakthrough is detailed in a publication in Nature Physics, where it reveals the introduction of an entirely new category of qubits that are optically interconnected. As the field of quantum networking progresses, the need for stable, scalable, and adaptable quantum nodes has become increasingly evident. The research team’s focus on quantum dots is particularly advantageous, as these nanoscale entities possess unique optical and electronic attributes intrinsic to quantum mechanical phenomena.
Quantum dots have demonstrated considerable potential in existing technologies, such as medical imaging and display screens, primarily due to their efficacy as bright single-photon sources. However, to create functional quantum networks, it is essential not only to emit single photons but also to establish reliable qubits that can effectively interact with these emitted photons. Moreover, these qubits must be capable of locally storing quantum information over extended periods. The researchers’ development enhances the inherent spins of the nuclear atoms within the quantum dots, optimizing them into a cohesive many-body quantum register.
Scientists have successfully achieved a quantum collective behavior of macroscopic mechanical oscillators, unlocking new possibilities in quantum technology.
Quantum technologies are radically transforming our understanding of the universe. One emerging technology are macroscopic mechanical oscillators, devices that are vital in quartz watches, mobile phones, and lasers used in telecommunications. In the quantum realm, macroscopic oscillators could enable ultra-sensitive sensors and components for quantum computing, opening new possibilities for innovation in various industries.
Controlling mechanical oscillators at the quantum level is essential for developing future technologies in quantum computing and ultra-precise sensing. But controlling them collectively is challenging, as it requires near-perfect units, i.e. identical.
One of the key goals within the field of quantum computing is to achieve what is known as a quantum advantage. This term essentially describes the point after which a quantum computer can outperform a classical computer on a specific task or solve a problem that is beyond the reach of classical computers.
One task that could be used to demonstrate a quantum advantage, known as quantum random sampling, entails the generation of samples from a probability distribution. This task is very difficult for classical computers to perform, but it could theoretically be completed by quantum computers.
While past studies have successfully tackled random sampling tasks using quantum computers, actually verifying that a system effectively performs these tasks has proved challenging. This is because many existing verification techniques based on classical data are either too computationally demanding or difficult to apply to larger quantum systems.
Quantum researchers from CSIRO, Australia’s national science agency, have demonstrated the potential for quantum computing to significantly improve how we solve complex problems involving large datasets, highlighting the potential of using quantum in areas such as real-time traffic management, agricultural monitoring, health care, and energy optimization.
By leveraging the unique properties of quantum computing, like superposition and entanglement, researchers compressed and analyzed a large dataset with speed, accuracy, and efficiency that traditional computers cannot match.
The work is published in the journal Advanced Science.
A Franco-German research team, including members from the University of Freiburg, shows that supramolecular chemistry enables efficient spin communication through hydrogen bonds. The work is published in the journal Nature Chemistry.
Qubits are the basic building blocks of information processing in quantum technology. An important research question is what material they will actually consist of in technical applications. Molecular spin qubits are considered promising qubit candidates for molecular spintronics, in particular for quantum sensing. The materials studied here can be stimulated by light; this creates a second spin center and, subsequently, a light-induced quartet state.
Until now, research has assumed that the interaction between two spin centers can only be strong enough for successful quartet formation if the centers are covalently linked. Due to the high effort required to synthesize covalently bonded networks of such systems, their use in application-related developments in the field of quantum technology is severely limited.
An algorithm allows the states of certain quantum systems to be determined from data more quickly than was previously possible.
Needham raised the firm’s price target on D-Wave Quantum (QBTS) to $8.50 from $2.25 and keeps a Buy rating on the shares as part of a broader research note on Quantum Computing names. Over the past several months, the combination of technical milestone achievements, announcements of quantum contract awards of increasing dollar value and mentions of quantum computing by leading technology CEOs has increased awareness of the potential opportunity for quantum computing among mainstream investors, and reflecting this increased awareness, the stock prices of pure play quantum computing companies have increased several fold since September 30, 2024, the analyst tells investors in a research note. s. 5.9% for the S&P 500. The increasing valuations for quantum computing companies reflect growing recognition that quantum computing may disrupt a meaningful portion of the $1T computing market over the next decade, the firm added.
In a ground-breaking theoretical study, two physicists have identified a new class of quasiparticle called the paraparticle. Their calculations suggest that paraparticles exhibit quantum properties that are fundamentally different from those of familiar bosons and fermions, such as photons and electrons respectively.
Using advanced mathematical techniques, Kaden Hazzard at Rice University in the US and his former graduate student Zhiyuan Wang, now at the Max Planck Institute of Quantum Optics in Germany, have meticulously analysed the mathematical properties of paraparticles and proposed a real physical system that could exhibit paraparticle behaviour.
“Our main finding is that it is possible for particles to have exchange statistics different from those of fermions or bosons, while still satisfying the important physical principles of locality and causality,” Hazzard explains.
For example, to compute the magnetic susceptibility, we simply select the operator \(A=\beta {({S}^{z})}^{2}\), where β = 1/T is the inverse temperature. Interestingly, this method of estimating thermal expectation values is insensitive to uniform spectral broadening of each peak, due to a cancellation between the numerator and denominator (see discussion resulting in equation (S69) in Supplementary Information). However, it is highly sensitive to noise at low ω, which is exponentially amplified by e−βω. To address this, we estimate the SNR for each DA(ω) independently and zero-out all points with SNR below three times the average SNR. This potentially introduces some bias by eliminating peaks with low signal but ensures that the effects of shot noise are well controlled.
To quantify the effect of noise on the engineered time dynamics, we simulate a microscopic error model by applying a local depolarizing channel with an error probability p at each gate. This results in a decay of the obtained signals for the correlator \({D}_{R}^{A}(t)\). The rate of the exponential decay grows roughly linearly with the weight of the measured operators (Extended Data Fig. 2). This scaling with operator weight can be captured by instead applying a single depolarizing channel at the end of the time evolution, with a per-site error probability of γt with an effective noise rate γ. This effective γ also scales roughly linear as a function of the single-qubit error rate per gate p (Extended Data Fig. 2).
Quantum simulations are constrained by the required number of samples and the simulation time needed to reach a certain target accuracy. These factors are crucial for determining the size of Hamiltonians that can be accessed for particular quantum hardware.