Amazon’s quantum computing service is currently good for learning about quantum computing and developing NISQ-regime quantum algorithms, but stay tuned.
Category: quantum physics – Page 574
Methods: In this review, due to their promise, we focus on inorganic nanomaterials [such as hollow mesoporous silica nanoparticles (HMSNs), tungsten sulfide quantum dots (WS2QDs), and gold nanorods (AuNRs)] combining PTT with CHT, RT or IT in one treatment, aiming to provide a comprehensive understanding of PTT-based combinational cancer therapy. Results: This review found much evidence for the use of inorganic nanoparticles for PTT-based combinational cancer therapy. Conclusion: Under synergistic effects, inorganic nanomaterial-based combinational treatments exhibit enhanced therapeutic effects compared to PTT, CHT, RT, IT or PDT alone and should be further investigated in the cancer field.
Applications of inorganic nanomaterials in photothermal therapy based on combinational cancer treatment — pubmed.
At these temperatures, the atoms move extremely slowly and can be controlled through quantum mechanical effects that are negligible at higher temperatures.
The team used lasers to excite the atoms and coax them into one shared motion. They found that when the atoms act collectively, they can shape and steer light through their electrical and magnetic interactions with it. The shared behavior allows them to act like a collection of electric charges or very small magnets that affect the light.
The emergence of artificial intelligence and machine learning techniques is changing the world dramatically with novel applications such as internet of things, autonomous vehicles, real-time imaging processing and big data analytics in healthcare. In 2020, the global data volume is estimated to reach 44 Zettabytes, and it will continue to grow beyond the current capacity of computing and storage devices. At the same time, the related electricity consumption will increase 15 times by 2030, swallowing 8% of the global energy demand. Therefore, reducing energy consumption and increasing speed of information storage technology is in urgent need.
Berkeley researchers led by HKU President Professor Xiang Zhang when he was in Berkeley, in collaboration with Professor Aaron Lindenberg’s team at Stanford University, invented a new data storage method: They make odd numbered layers slide relative to even-number layers in tungsten ditelluride, which is only 3nm thick. The arrangement of these atomic layers represents 0 and 1 for data storage. These researchers creatively make use of quantum geometry: Berry curvature, to read information out. Therefore, this material platform works ideally for memory, with independent ‘write’ and ‘read’ operation. The energy consumption using this novel data storage method can be over 100 times less than the traditional method.
This work is a conceptual innovation for non-volatile storage types and can potentially bring technological revolution. For the first time, the researchers prove that two-dimensional semi-metals, going beyond traditional silicon material, can be used for information storage and reading. This work was published in the latest issue of the journal Nature Physics[1]. Compared with the existing non-volatile (NVW) memory, this new material platform is expected to increase storage speed by two orders and decrease energy cost by three orders, and it can greatly facilitate the realization of emerging in-memory computing and neural network computing.
Simulating chemical processes is one of the most promising applications of quantum computers, but problems with noise have prevented nascent quantum systems from outperforming conventional computers on such tasks. Now, researchers at Google have taken a major step towards this goal by using the most powerful quantum computer yet built to successfully implement a protocol for calculating the electronic structure of a molecule. The results may form a blueprint for complex, useful calculations on quantum computers affected by noise.
In October 2019, Google announced to great fanfare that its 53-qubit Sycamore computer had achieved quantum advantage. This means that a quantum computer can solve at least one problem much faster than any conventional supercomputer. However, Google researchers openly acknowledged that the problem Sycamore solved (sampling the outcome of a random quantum circuit) is easy for a quantum computer but difficult for a conventional supercomputer — and had little practical use.
What researchers would really like to do is use quantum computers to solve useful problems more effectively than possible with conventional computers: “Sycamore is extremely programmable and, in principle, you really can run any algorithm on it…In this sense, it’s a universal quantum computer,” explains team member Ryan Babbush of Google Research, “However, there’s a heavy caveat: there’s still noise affecting the device and as a result we’re still limited in the size of circuit we can implement.” Such noise, which results from classical sources such as thermal interference, can destroy the fragile superpositions crucial to quantum computation: “We can implement a completely universal circuit before the noise catches up and eventually destroys the computation,” says Babbush.
New experimental evidence of a collective behavior of electrons to form “quasiparticles” called “anyons” has been reported by a team of scientists at Purdue University.
Anyons have characteristics not seen in other subatomic particles, including exhibiting fractional charge and fractional statistics that maintain a “memory” of their interactions with other quasiparticles by inducing quantum mechanical phase changes.
Postdoctoral research associate James Nakamura, with assistance from research group members Shuang Liang and Geoffrey Gardner, made the discovery while working in the laboratory of professor Michael Manfra is a Distinguished Professor of Physics and Astronomy, Purdue’s Bill and Dee O’Brien Chair Professor of Physics and Astronomy, professor of electrical and computer engineering, and professor of materials engineering. Although this work might eventually turn out to be relevant to the development of a quantum computer, for now, Manfra said, it is to be considered an important step in understanding the physics of quasiparticles.
Xanadu, a photonic quantum computing company, announced today the release of the world’s first publicly available photonic quantum cloud platform, according to a press release. Developers can now access Xanadu’s gate-based photonic quantum processors, in 8, 12, and soon 24-qubit machines.
Photonics based quantum computers have many advantages over older platforms. Xanadu’s quantum processors operate at room temperature. They can easily integrate into existing fiber optic-based telecommunication infrastructure, enabling a future where quantum computers are networked. It also offers great scalability supporting fault tolerance, owing to robust error-resistant physical qubits and flexibility in designing error correction codes. Xanadu’s unique type of qubit is based on squeezed states – a special type of light generated by our own chip-integrated silicon photonic devices.
“We believe that photonics offers the most viable approach towards universal fault-tolerant quantum computing with Xanadu’s ability to network a large number of quantum processors together. We are excited to provide this ecosystem, a world-first for both quantum and classical photonics,” said Christian Weedbrook, Xanadu Founder and CEO. “Our architecture is new, designed to scale-up like the Internet versus traditional mainframe-like approaches to quantum computing.”
A downsized version of the company’s Sycamore chip performed a record-breaking simulation of a chemical reaction.
Spiros Michalakis is the Caltech quantum physicist who served as the science advisor on Bill & Ted: Face The Music and he was kind enough to sit down and chat about quantum physics, the nature of time, and the brilliant minds behind Bill & Ted.
Check out IQIM at http://www.iqim.caltech.edu
Here’s the video featuring Paul Rudd playing chess with Stephen Hawking:
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Although we are currently in an era of quantum computers with tens of noisy qubits, it is likely that a decisive, practical quantum advantage can only be achieved with a scalable, fault-tolerant, error-corrected quantum computer. Therefore, development of quantum error correction is one of the central themes of the next five to ten years. Our article “Topological and subsystem codes on low-degree graphs with flag qubits” [1], published in Physical Review X, takes a bottom-up approach to quantum error correcting codes that are adapted to a heavy-hexagon lattice – a topology that all our new premium quantum processors use, including IBM Quantum Falcon (d=3) and Hummingbird (d=5).
Many in the quantum error correction community pursue a top-down computer science approach, i.e., designing the best codes from an abstract perspective to achieve the smallest logical error rate with minimal resource. Along this path, the surface code is the most famous candidate for near-term demonstrations (as well as mid- to long-term applications) on a two-dimensional quantum computer chip. The surface code naturally requires a two-dimensional square lattice of qubits, where each qubit is coupled to four neighbors.
We started with the surface code architecture on our superconducting devices and demonstrated an error detection protocol as a building block of the surface code around 2015 [2]. While the experimental team at IBM made steady progress with cross-resonance (CR) gates, achieving gate fidelities near 99%, an experimental obstacle appeared along the path of scaling up the surface code architecture. The specific way to operate the CR gates requires the control qubit frequency to be detuned from all its neighboring target qubits, such that the CNOT gates between any pair of control and target can be individually addressed.