Fast, ultra-bright photon source brings scalable quantum photonics within reach. Super-fast quantum computers and communication devices could revolutionize countless aspects of our lives — but first, researchers need a fast, efficient source of the entangled pairs of photons such systems use to tra.
THE FINANCE industry has had a long and profitable relationship with computing. It was an early adopter of everything from mainframe computers to artificial intelligence (see timeline). For most of the past decade more trades have been done at high frequency by complex algorithms than by humans. Now big banks have their eyes on quantum computing, another cutting-edge technology.
A fundamentally new kind of computing will shake up finance—the question is when.
Finance & economics Dec 19th 2020 edition.
Continue reading “Wall Street’s latest shiny new thing: quantum computing” »
The crystalline solid BaTiS3 (barium titanium sulfide) is terrible at conducting heat, and it turns out that a wayward titanium atom that exists in two places at the same time is to blame.
The discovery, made by researchers from Caltech, USC, and the Department of Energy’s Oak Ridge National Laboratory (ORNL), was published on November 27 in the journal Nature Communications. It provides a fundamental atomic-level insight into an unusual thermal property that has been observed in several materials. The work is of particular interest to researchers who are exploring the potential use of crystalline solids with poor thermal conductivity in thermoelectric applications, in which heat is directly converted into electric energy and vice versa.
“We have found that quantum mechanical effects can play a huge role in setting the thermal transport properties of materials even under familiar conditions like room temperature,” says Austin Minnich, professor of mechanical engineering and applied physics at Caltech and co-corresponding author of the Nature Communications paper.
The journey to see future technology starts in 2022, when Elon Musk and SpaceX send the first Starship to Mars — beginning the preparations for the arrival of the first human explorers.
We see the evolution of space exploration, from NASA’s Artemis mission, humans landing on Mars, and the interplanetary internet system going online. To the launch of the Starshot Alpha Centauri program, and quantum computers designing plants that can survive on Mars.
Continue reading “TIMELAPSE OF FUTURE TECH: From 2022 — 4000+” »
Scientists at Fermilab in the U.S. have demonstrated, for the first time, sustained and long-distance teleportation of qubits of photons with fidelity greater than 90%.
New research, published in Nature, has measured highly sought-after Majorana quantum states. A team of theoretical and experimental physicists have designed a new ultra-thin material that they have used to create elusive quantum states. Called one-dimensional Majorana zero energy modes, these quantum states could have a huge impact for quantum computing.
Quantum computational advantage or supremacy is a long-anticipated milestone toward practical quantum computers. Recent work claimed to have reached this point, but subsequent work managed to speed up the classical simulation and pointed toward a sample size–dependent loophole. Quantum computational advantage, rather than being a one-shot experimental proof, will be the result of a long-term competition between quantum devices and classical simulation. Zhong et al. sent 50 indistinguishable single-mode squeezed states into a 100-mode ultralow-loss interferometer and sampled the output using 100 high-efficiency single-photon detectors. By obtaining up to 76-photon coincidence, yielding a state space dimension of about 1030, they measured a sampling rate that is about 1014-fold faster than using state-of-the-art classical simulation strategies and supercomputers.
Science, this issue p. 1460
Quantum computers promise to perform certain tasks that are believed to be intractable to classical computers. Boson sampling is such a task and is considered a strong candidate to demonstrate the quantum computational advantage. We performed Gaussian boson sampling by sending 50 indistinguishable single-mode squeezed states into a 100-mode ultralow-loss interferometer with full connectivity and random matrix—the whole optical setup is phase-locked—and sampling the output using 100 high-efficiency single-photon detectors. The obtained samples were validated against plausible hypotheses exploiting thermal states, distinguishable photons, and uniform distribution. The photonic quantum computer, Jiuzhang, generates up to 76 output photon clicks, which yields an output state-space dimension of 1030 and a sampling rate that is faster than using the state-of-the-art simulation strategy and supercomputers by a factor of ~1014.
On December 3, Science magazine published a scientific paper by Chinese scientists on the results of experiments with a prototype quantum computer.
It was widely reported in the media that the Chinese system needed only 200 seconds to carry out a computation that would take over two billion years using the fastest supercomputer existing today.
The experiments were designed and carried out by a top-level research group led by Pan Jianwei and Lu Chaoyang of the University of Science and Technology in Hefei, China. Pan is one of the most famous Chinese physicists today, referred to once in Nature magazine as the “Father of the Quantum.”
Quantum key distribution is one kind of important cryptographic protocols based on quantum mechanics, in which any outside eavesdropper attempting to obtain the secret key shared by two users will be detected. The successful detection comes from Heisenberg’s uncertainty principle: the measurement of a quantum system, which is required to obtain information of that system, will generally disturb it. The disturbances provide two users with the information that there exists an outside eavesdropper, and they can therefore abort the communication. Nowadays, most people need to share some of their private information for certain services such as products recommendation for online shopping and collaborations between two companies depending on their comm interests. Private Set Intersection Cardinality (PSI-CA) and Private Set Union Cardinality (PSU-CA), which are two primitives in cryptography, involve two or more users who intend to obtain the cardinalities of the intersection and the union of their private sets through the minimum information disclosure of their sets1,2,3.
The definition of Private Set Intersection (PSI), also called Private Matching (PM), was proposed by Freedman4. They employed balanced hashing and homomorphic encryption to design two PSI protocols and also investigated some variants of PSI. In 2012, Cristofaro et al.1 developed several PSI-CA and PSU-CA protocols with linear computation and communication complexity based on the Diffie-Hellman key exchange which blinds the private information. Their protocols were the most efficient compared with the previous classical related ones. There are also other classical PSI-CA or PSU-CA protocols5,6,7,8. Nevertheless, the security of these protocols relies on the unproven difficulty assumptions, such as discrete logarithm, factoring, and quadratic residues assumptions, which will be insecure when quantum computers are available9,10,11.
For the sake of improving the security of PSI-CA protocols for two parties, Shi et al.3 designed a probabilistic protocol where multi-qubit entangled states, complicated oracle operators, and measurements in high N-dimensional Hilbert space were utilized. And the same method in Ref.3 was later used to develop a PSI-CA protocol for multiple parties12. For easy implementation of a protocol, Shi et al.13 leveraged Bell states to construct another protocol for PSI-CA and PSU-CA problems that was more practical than that in Ref.3. In both protocols Ref.3 and Ref.13, only two parties who intend to get the cardinalities of the intersection and the union of their private sets are involved. Although Ref.12 works for multiple parties, it only solves the PSI-CA problem and requires multi-qubit entangled states, complicated oracle operators, and measurements. It then interests us that how we could design a more practical protocol for multiple parties to simultaneously solve PSI-CA and PSU-CA problems. Inspired by Shi et al.’s work, we are thus trying to design a three-party protocol to solve PSI-CA and PSU-CA problems, where every two and three parties can obtain the cardinalities of the intersection and the union of their respective private sets with the aid of a semi-honest third party (TP). TP is semi-honest means that he loyally executes the protocol, makes a note of all the intermediate results, and might desire to take other parties’ private information, but he cannot collude with dishonest parties. We then give a detailed analysis of the presented protocol’s security. Besides, the influence of six typical kinds of Markovian noise on our protocol is also analyzed.
Super-fast quantum computers and communication devices could revolutionize countless aspects of our lives—but first, researchers need a fast, efficient source of the entangled pairs of photons such systems use to transmit and manipulate information. Researchers at Stevens Institute of Technology have done just that, not only creating a chip-based photon source 100 times more efficient that previously possible, but bringing massive quantum device integration within reach.
“It’s long been suspected that this was possible in theory, but we’re the first to show it in practice,” said Yuping Huang, Gallagher associate professor of physics and director of the Center for Quantum Science and Engineering.
To create photon pairs, researchers trap light in carefully sculpted nanoscale microcavities; as light circulates in the cavity, its photons resonate and split into entangled pairs. But there’s a catch: at present, such systems are extremely inefficient, requiring a torrent of incoming laser light comprising hundreds of millions of photons before a single entangled photon pair will grudgingly drip out at the other end.
