Phys.org August 26, 2024 Ghost imaging in the time domain allows for reconstructing fast temporal objects using a slow photodetector. The technique involves correlating random or pre-programmed probing temporal intensity patterns with the integrated signal measured after modulation by the temporal object. However, the implementation of temporal ghost imaging necessitates ultrafast detectors or modulators for measuring or pre-programming the probing intensity patterns, which are not available in all spectral regions especially in the mid-infrared range. An international team of researchers (China, Finland) demonstrated a frequency down conversion temporal ghost imaging scheme that enables to extend the operation regime to arbitrary […]
Reconfigurable sensor can detect particles 0.001 times the wavelength of light
Phys.org August 27, 2024 The exceptional point, a spectral singularity widely existing in non-Hermitian systems, provides an indispensable route to enhance the sensitivity of optical detection. However, the exceptional point of the systems is set once the system is built or fabricated, and machining errors make it hard to reach such a state precisely. An international team of researchers (China, Spain, Singapore) developed a highly tunable and reconfigurable exceptional point system, i.e., a single spoof plasmonic resonator suspended above a substrate and coupled with two freestanding Rayleigh scatterers. Their design offered great flexibility to control exceptional point states, enabling them […]
Sound drives ‘quantum jumps’ between electron orbits
Phys.org August 26, 2024 Coherent quantum control is an essential tool for understanding and mitigating decoherence. Characterizing and controlling orbital states is a central challenge for quantum networking, where optical coherence is tied to orbital coherence. Researchers at Cornell University studied resonant multi phonon orbital Rabi oscillations extracting the strength of the orbital-phonon interactions and the coherence of the acoustically driven orbital states. They reached the strong-driving limit, where the physics was dominated by coupling induced by the acoustic waves. They found agreement between their measurements, quantum master-equation simulations, and a Landau-Zener transition model in the strong-driving limit. They modeled […]
Study of disordered rock salts leads to battery breakthrough
MIT News August 23, 2024 Co- and Ni-free disordered rock salt cathodes utilize oxygen redox to increase the energy density of lithium-ion batteries, but it is challenging to achieve good cycle life at high voltages >4.5 V. An international team of researchers (USA – MIT, Pennsylvania State University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Brookhaven National Laboratory, South Korea, Canada, China, Taiwan) found a family of Li-excess Mn-rich cathodes that integrates rock salt- and polyanion-type structures. Following design rules for cation filling and ordering, they demonstrated the bulk incorporation of polyanion groups into the rock salt lattice. This integration bridged […]
Study proposes generalized approach to light-matter interactions
Phys.org August 26, 2024 An international team of researchers (USA – University of Chicago, Italy) described a solution for the eigenstate problem of mixed fermion-boson systems that could be implemented on quantum devices. Based on a generalization of the electronic contracted Schrödinger equation (CSE), they guided a trial wave function to the ground state of any arbitrary mixed Hamiltonian by directly measuring residuals of the mixed CSE on a quantum device. The accuracy of their approach was not limited by the unknown exchange-correlation functional or the uncontrolled form of the exponential assumption. To test the performance of the method, they […]
Test of a prototype quantum internet runs under New York City for half a month
Phys.org August 24, 2024 The distribution of high-fidelity high-rate entanglement over telecommunication infrastructure is one of the main paths toward large-scale quantum networks, enabling applications such as quantum encryption and network protection, blind quantum computing, distributed quantum computing, and distributed quantum sensing. However, the fragile nature of entangled photons operating in real-world fiber infrastructure has historically limited continuous operation of such networks. A company in New York presented a fully automated system capable of distributing polarization-entangled photons over a 34-km deployed fiber in New York City, achieving high rates of nearly 5×105 pairs/s. They demonstrated high fidelity of approximately 99% […]
Toward a code-breaking quantum computer
MIT News August 23, 2024 Researchers at MIT made two improvements to Regev’s quantum factoring algorithm by addressing its space efficiency and its noise-tolerance. They improved the quantum space efficiency of Regev’s algorithm by constructing a quantum factoring circuit using O(n log n) qubits and O(n3/2log n) gates. achieving the best of Shor and Regev gates. Optimization was achieved by implementing efficient and reversible exponentiation with Fibonacci numbers in the exponent, rather than the usual powers of 2. This technique allowed them to perform quantum modular exponentiation that was efficient in both space and size without requiring significant precomputation, a […]
World’s first micromachine twists 2D materials at will
Phys.org August 22, 2024 Two-dimensional materials (2DM) and their heterostructures offer tunable electrical and optical properties, primarily modifiable through electrostatic gating and twisting. Although electrostatic gating is a well-established method for manipulating Two-dimensional materials (2DM), achieving real-time control over interfacial properties remains challenging in exploring 2DM physics and advanced quantum device technology. Current methods are limited in their scope of application, lacking the accessibility and scalability of electrostatic gating at the device level. An international team of researchers (USA – Harvard University, MIT, Stanford University, UC Berkeley, Japan) introduced an on-chip platform for 2DM with in situ adjustable interfacial properties, […]
Top 10 Science and Technology Inventions for the Week of August 23, 2024
01. Morphable materials: Researchers coax nanoparticles to reconfigure themselves 02. New software tool aims to reduce reliance on animal testing 03. Printed electronics material can store 1,000 times more charge than current forms 04. Researchers observe ‘locked’ electron pairs in a superconductor cuprate 05. Ultrathin quantum light sources: Scientists show excitonic interactions boost efficiency of entangled photon generation 06. Advanced orbital angular momentum mode switching in multimode fiber utilizing an optical neural network chip 07. MIT engineers design tiny batteries for powering cell-sized robots 08. Scientists investigate triggers of explosive volcanic eruptions in lab simulation study 09. Smart fabrics detect […]
Advanced orbital angular momentum mode switching in multimode fiber utilizing an optical neural network chip
Phys.org August 21, 2024 Existing optical switching solutions are inadequate for addressing flexible information exchange among the mode channels. Researchers in China introduced a flexible mode switching system in a multimode fibre based on an optical neural network chip. The system utilized the flexibility of on-chip optical neural networks along with an all-fibre orbital angular momentum (OAM) mode multiplexer-demultiplexer to achieve mode switching among the three OAM modes within a multimode fibre. They validated the system by successfully transmitting different modulation formats across various modes. According to the researchers their system could provide effective optical switching in practical multimode communication […]