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Archive for the ‘quantum physics’ category: Page 18

Nov 28, 2024

Quantum Breakthrough: Atoms held in quantum superposition for more than 23 minutes

Posted by in categories: particle physics, quantum physics

Quantum mechanics, a realm of the incredibly small, is often characterized by its paradoxical nature. One such paradox is the concept of superposition, where a quantum particle can exist in multiple states simultaneously. These delicate states, however, are notoriously fragile, often collapsing into a single, definite state within mere fractions of a second. Yet, a recent breakthrough has pushed the boundaries of quantum stability, achieving a record-breaking 23-minute lifespan for a specific type of superposition known as a cat state.

The term “cat state” is a whimsical reference to Schrödinger’s famous thought experiment, where a cat is placed in a box with a device that could randomly kill it. Until the box is opened, the cat is both alive and dead, a superposition of two states. In quantum mechanics, cat states manifest when a quantum object, such as an atom or a photon, exists in multiple states simultaneously, defying classical intuition.

While researchers have previously created cat states in laboratories, these states have been fleeting, quickly succumbing to the disruptive influence of their environment. However, a team led by Zheng-Tian Lu at the University of Science and Technology of China has managed to extend the lifespan of a cat state dramatically. They achieved this feat by manipulating a cloud of 10,000 ytterbium atoms, cooled to near absolute zero and trapped by laser light. By carefully controlling the atoms’ quantum states, the researchers were able to induce a superposition where each atom existed in two distinct spin states simultaneously.

Nov 28, 2024

Scientists Crack Quantum Computing Complexity With Revolutionary Hybrid Design

Posted by in categories: computing, information science, quantum physics

Quantum computers operate using quantum gates, but the complexity and large number of these gates can diminish their efficiency. A new “hybrid” approach reduces this complexity by utilizing natural system interactions, making quantum algorithms easier to execute.

This innovation helps manage the inherent “noise” issues of current quantum systems, enhancing their practical use. The approach has been effectively demonstrated with Grover’s algorithm, enabling efficient searches of large datasets without extensive error correction.

Challenges of Quantum Computing.

Nov 28, 2024

Atoms moved from one place to another via quantum tunneling in a first

Posted by in categories: particle physics, quantum physics

In order to achieve the tunneling of atoms, the researchers used three optical tweezers and arranged them in a series. Then they introduced ultracold fermionic atoms (atoms that are cooled down to absolute zero temperatures) in this arrangement.

Using the three tweezers as traps, the researchers were able to control the tunneling rate of atoms by changing the distance between the traps. This approach allowed the researchers to successfully transfer atoms between the two outer tweezers.

“We observe a smooth and high-efficiency transfer of atoms between the two outer traps, with a very low population remaining in the central trap,” the researchers note in their study.

Nov 28, 2024

Atoms transferred between optical tweezers via quantum tunneling in a first

Posted by in categories: 3D printing, bioprinting, biotech/medical, quantum physics

Researchers at the University of Twente, Netherlands, have made an advancement in bioprinting technology that could transform how we create vascularized tissues. Their innovative bioink, recently featured in Advanced Healthcare Materials, introduces a way to precisely guide the growth and organization of tiny blood vessels within 3D-bioprinted tissues. The tiny blood vessels mimic the intricate networks found in the human body.

3D-printed organs have the potential to revolutionize medicine by providing solutions for organ failure, and tissue damage and developing new therapies. But a major challenge is ensuring these printed tissues receive enough nutrients and oxygen, which is critical for their survival and function. Without blood vessels, these tissues can’t efficiently obtain nutrients or remove waste, limiting their effectiveness. Therefore, the ability to 3D-bioprint blood vessels is a crucial advancement.

Tissue engineers could already position blood vessels during the bioprinting process, but these vessels often remodel unpredictably when cultured in the lab or implanted in the body, reducing the effectiveness of the engineered tissue. The programmable bioink developed by the University of Twente team addresses this issue by providing dynamic control over vessel growth and remodeling over time. This opens new possibilities for creating engineered tissues with long-term functionality and adaptability.

Nov 28, 2024

A pathway toward new quantum devices: Electrically defined quantum dots in zinc oxide

Posted by in categories: computing, quantum physics

Researchers have successfully created electrically defined quantum dots in zinc oxide (ZnO) heterostructures, marking a significant milestone in the development of quantum technologies.

Details of their breakthrough were published in the journal Nature Communications on November 7, 2024.

Quantum dots, tiny semiconductor structures that can trap electrons in nanometer-scale spaces, have long been studied for their potential to serve as qubits in quantum computing. These dots are crucial for quantum computing because they allow scientists to control the behavior of electrons, similar to how a conductor might control a current of water flowing through pipes.

Nov 28, 2024

Making quantum physics easier to digest in schools: Experts encourage focus on two-state systems

Posted by in categories: education, quantum physics

A team of physics educators from Italy, Hungary, Slovenia and Germany is focusing on a new approach to teaching quantum physics in schools. Traditional classroom teaching has tended to focus on presenting the history of the origins of quantum physics, which often poses problems for learners.

Using the quantum measurement process as an example, the researchers have now published their first empirical findings on learning —based on two-state systems—in Physical Review Physics Education Research.

The researchers, including physics education specialist Professor Philipp Bitzenbauer from Leipzig University, concentrate on what are known as qubits. These are two-state systems, the simplest and at the same time most important quantum systems that can be used to describe many situations. Controlling and manipulating these qubits plays a central role in modern quantum technologies.

Nov 28, 2024

Quantum Breakthrough Allows Researchers To Create “Previously Unimaginable Nanocrystals”

Posted by in categories: biotech/medical, chemistry, quantum physics, solar power

The type of semiconductive nanocrystals known as quantum dots is not only expanding the forefront of pure science but also playing a crucial role in practical applications, including lasers, quantum QLED televisions and displays, solar cells, medical devices, and other electronics.

A new technique for growing these microscopic crystals, recently published in Science, has not only found a new, more efficient way to build a useful type of quantum dot, but also opened up a whole group of novel chemical materials for future researchers’ exploration.

“I am excited to see how researchers across the globe can harness this technique to prepare previously unimaginable nanocrystals,” said first author Justin Ondry, a former postdoctoral researcher in UChicago’s Talapin Lab.

Nov 28, 2024

Quantum Computing Breakthrough Achieves 99.98% Gate Fidelity

Posted by in categories: computing, quantum physics

Researchers have achieved high gate fidelities up to 99.98% using a new double-transmon coupler. This development enhances quantum computing performance and supports the advancement toward fault-tolerant systems.

Researchers from the RIKEN Center for Quantum Computing and Toshiba have developed a quantum computer gate using a double-transmon coupler (DTC), a device previously proposed in theory to enhance the fidelity of quantum gates significantly. With this innovation, the team achieved a fidelity of 99.92% for a two-qubit device known as a CZ gate and 99.98% for a single-qubit gate.

This milestone, part of the Q-LEAP project, not only improves the performance of noisy intermediate-scale quantum (NISQ) devices but also lays the groundwork for fault-tolerant quantum computation through more effective error correction.

Nov 28, 2024

Cooling With Light: Solid-State Optical Cooling Using Quantum Dots

Posted by in categories: energy, quantum physics

https://www.eurekalert.org/news-releases/1065953

Researchers have explored a fascinating cooling phenomenon within halide perovskite-based “dots-in-crystal” materials, uncovering both their promise and challenges.

In a groundbreaking study, scientists from Chiba University investigated the potential of solid-state optical cooling through perovskite quantum dots. Central to their research was anti-Stokes photoluminescence, a rare process where materials emit photons with higher energy than those absorbed. This innovative approach could transform cooling technology, offering a path to more efficient, energy-saving solutions. Their work not only highlights the immense promise of this technique but also reveals key limitations that pave the way for further advancements in the field.

Nov 27, 2024

Toshiba’s Double-Transmon Coupler for Superconducting Quantum Computers Achieves 99.9% Fidelity

Posted by in categories: computing, quantum physics

PRESS RELEASE —-Toshiba Corporation (Toshiba) has confirmed a technology that they claimed promises to advance progress toward the development of higher-performance quantum computers through an investigation of a potential advance in quantum computing. Experiments conducted by a joint research group from Toshiba and RIKEN, one of Japan’s largest comprehensive research institutions, have successfully realized a Double-Transmon Coupler, a solution for superconducting quantum computers initially proposed by Toshiba. The researchers achieved a world-class fidelity of 99.90% for a two-qubit gate, which is at the heart of quantum computation. Fidelity is a standard performance indicator for quantum gates, quantifying how close an operation is to the ideal in a range from 0% to 100%, with higher percentages indicating greater accuracy in the quantum gate’s operation.

Originally proposed by Toshiba in a paper from September 2022, the Double-Transmon Coupler is a tunable coupler that holds the key to improving the performance of superconducting quantum computers. In successful experimental realization, Toshiba and RIKEN have confirmed its theoretical superiority over conventional tunable couplers in suppressing the long-standing problem of unnecessary residual coupling and enabling high-speed, high-fidelity two-qubit gates.

To improve the performance of two-qubit gates, the coherence time, the period for which the quantum superposition state can be maintained — critical in quantum computers — must be extended. Gates must also be executed quickly and the strength of residual coupling must be suppressed to reduce the errors it causes. The Toshiba-RIKEN team achieved a world-class coherence time for the transmon qubit, a short gate time of 48 ns, and reduced the residual coupling strength to as low as 6 kHz, thereby achieving a fidelity of 99.90%.

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