Science Daily August 31, 2021 While components of the quantum Internet are under development, the control plane remains undefined. An international team of researchers (Canada, USA – industry) outline their vision for a software-defined quantum network that enables a flexible experimental platform for developing quantum applications for industry. The quantum Internet, like the classical Internet, will be a network of networks. Operation of an industrial quantum network is viewed as a networked control problem, and they propose a time-sensitive network control plane to enable a quantum software-defined network. Measurement-device-independent quantum key distribution is used as an example implementation since it […]
Tag Archives: Quantum technology
New quantum ‘stopwatch’ can improve imaging technologies
Phys.org August 24, 2021 Time-correlated single-photon counting (TCSPC) is an enabling technology for applications such as low-light fluorescence lifetime microscopy and photon counting time-of-flight (ToF) 3D imaging. However, state-of-the-art TCSPC single-photon timing resolution (SPTR) is limited to 3–100 ps by single-photon detectors. Researchers at the University of Colorado experimentally demonstrated a time-magnified TCSPC (TM-TCSPC) that achieves an ultrashort SPTR of 550 fs with an off-the-shelf single-photon detector. It can resolve ultrashort pulses with a 130-fs pulse width difference at a 22-fs accuracy. When applied to photon counting ToF 3D imaging, the it greatly suppresses the range walk error that limits […]
A complete platform for quantum computing
Phys.org August 13, 2021 A promising and potentially scalable hardware platforms and computational protocols is to combine a photonic platform with measurement-induced quantum information processing. Gate operations can be implemented through optical measurements on a cluster state. Researchers in Denmark designed and demonstrated the deterministic implementation of a multi-mode set of measurement-induced quantum gates in a large two-dimensional optical cluster state using phase-controlled continuous-variable quadrature measurements. Each gate is programmed into the phases of high-efficiency quadrature measurements, which execute the transformations by teleportation through the cluster state. They executed a small quantum circuit consisting of 10 single-mode gates and 2 […]
Engineers make critical advance in quantum computer design
Phys.org August 13, 2021 Advancing from the current few-qubit devices to silicon quantum processors with upward of a million qubits, as required for fault-tolerant operation, presents several unique challenges, one of the most demanding being the ability to deliver microwave signals for large-scale qubit control. Researchers in Australia have demonstrated a potential solution to this problem by using a three-dimensional dielectric resonator to broadcast a global microwave signal across a quantum nanoelectronic circuit. The technique uses only a single microwave source and can deliver control signals to millions of qubits simultaneously. They have shown that the global field can be […]
Scientists realize noiseless photon-echo protocol
Phys.org August 16, 2021 The intense spontaneous noise emission generated by photon echo is a fundamental tool for the manipulation of electromagnetic fields. However, it has the same frequency as the signal, and it is impossible to separate them in principle. Researchers in China have implemented a noiseless photon echo (NLPE) protocol in Eu3+:Y2SiO5 crystal to serve as an optical quantum memory and applied a four-level atomic system to suppress the noise. They manipulated the spontaneous noise emission to have a different frequency from the signal making it easier to separate the signal from the noise emission. Though other noises […]
Running quantum software on a classical computer
EurekAlert August 3, 2021 A key open question in quantum computing is whether quantum algorithms can potentially offer a significant advantage over classical algorithms for tasks of practical interest. An international team of researchers (USA – Flatiron Institute, Columbia University, Switzerland) has introduced a method to simulate layered quantum circuits consisting of parametrized gates suitable for near-term quantum computers. They used a neural-network parametrization of the many-qubit wavefunction focusing on states relevant for the Quantum Approximate Optimization Algorithm (QAOA). For the largest circuits simulated, they reached 54 qubits at 4 QAOA layers without requiring large-scale computational resources. For larger systems, […]
Spin-sonics: Acoustic wave gets the electrons spinning
Phys.org July 29, 2021 An international team of researchers (Germany, Canada, USA – Perdue University) has detected the rolling movement of a nano-acoustic wave predicted by Lord Rayleigh in 1885. They used an extremely fine nanowire that was positioned on lithium niobate, a piezoelectric material, which becomes deformed when subjected to an electrical current. With the aid of small metal electrodes, an acoustic wave can be generated on the material. The acoustic wave generates an elliptically rotating electrical field. This, in turn, forces the electrons in the nanowire onto circular paths. So far, this phenomenon was seen in light. Now […]
Unlocking radiation-free quantum technology with graphene
Nanowerk July 8, 2021 Making usable quantum technologies out of rare-earth compounds has remained a challenge because they contain critically radioactive compounds rendering them of limited use in real-world quantum technologies. An international team of researchers (Switzerland, Finland) used the sub-nanometre thickness of graphene to create heavy fermions. By layering thin sheets of carbon on top of one another in a specific pattern, where each sheet is rotated in relation to the other, it is possible to create the quantum properties effect that results in the electrons in the graphene behaving like heavy fermions. While in this work they showed the […]
Classic magic trick may enable quantum computing
Phys.org June 22, 2021 In a proof of principle experiment researchers at the DOE’s Thomas Jefferson National Accelerator Facility are preparing to trap and levitate particles inside a cavity using an electric field. Intrinsic characteristics of superconducting radiofrequency (SRF) cavities will overcome some limits of laser trapping. If they can levitate a particle, they might be able to impart a quantum state on it by cooling the trapped particle to its lowest possible energy level. A levitated particle in an SRF cavity that is under vacuum and chilled to super cold temperatures will only interact with the cavity’s electric field […]
Researchers create quantum microscope that can see the impossible
Phys.org June 9, 2021 The performance of light microscopes is limited by the stochastic nature of light. Randomness in the times that photons are detected introduces shot noise, which fundamentally constrains sensitivity, resolution, and speed. Although the long-established solution to this problem is to increase the intensity of the illumination light, this is not always possible when investigating living systems, because bright lasers can severely disturb biological processes. An international team of researchers (Australia, Germany) has experimentally shown that quantum correlations allow a signal-to-noise ratio beyond the photodamage limit of conventional microscopy. They developed a coherent Raman microscope that offers […]