Phys.org July 29, 2024 Researchers in the UK summarized recent progress in the development and applications of microstructured optical fibers for quantum technologies. The optical nonlinearity of solid-core and gas-filled hollow-core fibers provides a valuable medium for the generation of quantum resource states as well as for quantum frequency conversion between the operating wavelengths of existing quantum photonic material architectures. The low loss, low latency, and low dispersion of hollow-core fibers make these fibers particularly attractive for both short- and long-distance links in quantum networks. Hollow-core fibers also promise to replace free-space optical components in a wide range of atomic […]
Tag Archives: Quantum technologies
New method achieves tenfold increase in quantum coherence time via destructive interference of correlated noise
Phys.org July 10, 2024 Decoherence and imperfect control are crucial challenges for quantum technologies. Common protection strategies rely on noise temporal autocorrelation, which is not optimal if other correlations are present. An international team of researchers (Israel, Germany, USA – Caltech, industry) developed and experimentally demonstrated a strategy that used the cross-correlation of two noise sources. Utilizing destructive interference of cross-correlated noise extended the coherence time tenfold, improved control fidelity, and surpassed the state-of-the-art sensitivity for high frequency quantum sensing, significantly expanding the applicability of noise protection strategies… read more. Open Access TECHNICAL ARTICLE
Flat optics revolutionize quantum light sources for enhanced communication and sensing
Nanowerk April 25, 2024 Recent advancements have witnessed a significant shift toward the utilization of “flat” optics with thickness at subwavelength scales for the development of quantum light sources. This approach offers notable advantages over conventional bulky counterparts, including compactness, scalability, and improved efficiency, along with added functionalities. In this review researchers in Australia focused on the recent advances in leveraging flat optics to generate quantum light sources. Specifically, the generation of entangled photon pairs through spontaneous parametric down-conversion in nonlinear metasurfaces, and single photon emission from quantum emitters including quantum dots and color centers in 3D and 2D materials […]
A universal path for converting light into current in solids
Phys.org April 16, 2024 Harnessing the asymmetric electronic population in the conduction band induced by an intense single-color circularly polarized laser pulse an international team of researchers (Japan, India, Germany) developed a universal method to generate ultrafast photocurrent in both inversion-symmetric and inversion-broken Weyl semimetals with degenerate Weyl nodes at the Fermi level. They found that the induced photocurrent could be tailored by manipulating helicity and ellipticity of the employed laser. Their approach generated photocurrent in realistic situations when the Weyl nodes were positioned at different energies and had finite tilt along a certain direction. According to the researchers their […]
Valley-transistor in two-dimensional materials – an ingredient for all-optical quantum technologies
Nanowerk April 23, 2023 Electrons in two-dimensional materials possess an additional quantum attribute, the valley pseudospin, labeled as K and K’—analogous to the spin up and spin down. Most of the research to achieve valley-selective excitations in valleytronics depends on resonant circularly polarized light with a given helicity. Not only acquiring valley-selective electron excitation but also switching the excitation from one valley to another is quintessential for bringing valleytronics-based technologies to reality. Researchers in India introduced a coherent control protocol to initiate valley-selective excitation, de-excitation, and switch the excitation from one valley to another on the fly within tens of […]
Scientists turn single molecule clockwise or counterclockwise on demand
Phys.org December 21, 2022 Complexes containing rare-earth ions attract great attention for their technological applications ranging from spintronic devices to quantum information science. While charged rare-earth coordination complexes are ubiquitous in solution, they are challenging to form on materials surfaces that would allow investigations for potential solid-state applications. A team or researchers in the US (Argonne National Laboratory, Ohio University, University of Illinois) has demonstrated formation and atomically precise manipulation of rare-earth complexes on gold surface. Although they are composed of multiple units held together by electrostatic interactions, the entire complex rotates as a single unit when electrical energy is […]
Transporting of two-photon quantum states of light through a phase-separated Anderson localization optical fiber
Phys.org November 23, 2022 Experiments in the past have demonstrated Anderson localization in optical fibers, classical or conventional light, in two dimensions while propagating it through the third dimension. An international team of researchers (Spain, USA – industry, Italy) engineered the optical setup to send the quantum light through the phase-separated Anderson localization fiber and detected its arrival with the single-photon avalanche diode (SPAD) array camera. It enabled them not only to detect and identify them as pairs, as they arrived at the same time. As the pairs are quantum correlated, knowing where one of the two photons is detected […]
Researchers control individual light quanta at very high speed
Phys.org November 21, 2022 An international team of researchers (Spain, Germany) fabricated a dynamically reconfigurable integrated photonic circuit comprising integrated quantum dots (QDs), a Mach-Zehnder interferometer (MZI) and surface acoustic wave (SAW) transducers directly fabricated on a monolithic semiconductor platform to demonstrate on-chip single photon generation by the QD and its sub-nanosecond dynamic on-chip control. Two independently applied SAWs piezo-optomechanically rotated the single photon in the MZI. In the MZI, SAWs imprinted a time-dependent optical phase and modulated the qubit rotation to the output superposition state. This enabled dynamic single photon routing with frequencies exceeding one gigahertz. The combination of […]
New device gets scientists closer to quantum materials breakthrough
Phys.org June 17, 2022 An international team of researchers (USA – UC Berkeley, University of Nebraska, Argonne National Laboratory, Canada) has found a way to combine the advantages of light and matter at room temperature suitable for finding the global minimum of mathematical formulations at room temperature. They used solution-grown halide perovskite grown under nanoconfinement. This produced exceptional smooth single-crystalline large crystals with great optical homogeneity. Its material properties could enable future studies at room temperature rather than ultracold temperatures. They showed that XY spin lattice with many coherently coupled condensates that can be constructed as a lattice with a […]
Ultra-thin film of magnetite optimized for spintronics
Phys.org November 17, 2021 Magnetite has physical properties which may make it useful for spintronics technology. However, it is difficult to fabricate magnetite with high crystallinity owing to the imperfection of the substrate surface. An international team of researchers (Japan, China) has developed a chemical polishing technique—known by its acronym CARE—to prepare an atomically flat and highly ordered magnesium oxide substrate. CARE treatment of the substrate enabled the thin film to undergo a temperature-dependent resistivity change—known as the Verwey transition—of a factor of 5.9. The results have important applications – quantum computing technologies may rely on spintronics to optimize logistical, […]