Phys.org July 29, 2024 It remains a challenging task to efficiently trap a large ensemble of cold atoms on an integrated nanophotonic circuit. Researchers at Purdue University demonstrated direct loading of an ensemble of up to 70 atoms into an optical microtrap on a nanophotonic microring circuit by employing degenerate Raman-sideband cooling in the microtrap, where a built-in spin-motion coupling arose directly from the vector light shift of the evanescent-field potential on a microring. Atoms were cooled into the trap via optical pumping with a single free space beam. They achieved a trap lifetime approaching 700 ms under continuous cooling. […]
Category Archives: Transistors
Scientists discover way to ‘grow’ sub-nanometer sized transistors
Phys.org July 3, 2024 When the tilting angles are arbitrary, the grain boundaries in atomically thin van der Waals materials form inhomogeneous sublattices, giving rise to local electronic states that are not controlled. An international team of researchers (Korea, USA – Harvard University) has reported on epitaxial realizations of deterministic MoS2 mirror twin boundaries (MTBs) at which two adjoining crystals are reflection mirroring by an exactly 60° rotation by position-controlled epitaxy. They showed that these epitaxial MTBs were one-dimensionally metallic to a circuit length scale. They incorporated the epitaxial MTBs as a 1D gate to build integrated two-dimensional field-effect transistors […]
Quantum interference could lead to smaller, faster, and more energy-efficient transistors
Science Daily March 25, 2024 Quantum behaviour presents an unresolved challenge facing electronics at the few-nanometre scale: resistive channels start leaking owing to quantum tunnelling which affect the performance of nanoscale transistors, with direct source–drain tunnelling degrading switching ratios. The strategy to mitigate quantum effects has been to increase device complexity. An international team of researchers (UK, Canada, Italy) demonstrated how the performance of molecular transistors was improved when the resistive channel contained two destructively interfering waves. They used a zinc-porphyrin coupled to graphene electrodes in a three-terminal transistor to demonstrate a >104 conductance-switching ratio, a subthreshold swing at the […]
Researchers design switch-like proteins inspired by transistors
Phys.org August 23, 2023 In nature, proteins that switch between two conformations in response to environmental stimuli structurally transduce biochemical information in a manner analogous to how transistors control information flow in computing devices. Designing proteins with two distinct but fully structured conformations is a challenge for protein design as it requires sculpting an energy landscape with two distinct minima. A team of researchers in the US (University of Washington, Lawrence Berkeley National Laboratory, University of Milwaukee) described the design of “hinge” proteins that populate one designed state in the absence of ligand and a second designed state in the […]
Cutting edge transistors for semiconductors of the future
Science Daily July 3, 2023 Researchers in Sweden have demonstrated the integration of a ferroelectric gate stack on a heterostructure tunnel field-effect transistor (TFET) with subthermionic operation. Based on the ultrashort effective channel created by the band-to-band tunneling process, the localized potential variations induced by single domains and individual defects were sensed without physical gate-length scaling required for conventional transistors. They electrically measured abrupt threshold voltage shifts and quantified the appearance of new individual defects activated by the ferroelectric switching. According to the researchers their results show that ferroelectric films can be integrated on heterostructure devices and indicated that the […]
New germanium-tin transistor as alternative to silicon
Nanowerk April 28, 2023 The continued downscaling of silicon CMOS technology presents challenges for achieving the required low power consumption. While high mobility channel materials hold promise for improved device performance at low power levels, a material system which enables both high mobility n-FETs and p-FETs, that is compatible with Si technology and can be readily integrated into existing fabrication lines is required. An international team of researchers (Germany, France, UK) has developed high performance, vertical nanowire gate-all-around FETs based on the GeSn-material system grown on Si. While the p-FET transconductance was increased to 850 µS/µm by exploiting the small band […]
Solid-state thermal transistor demonstrated
Nanowerk February 21, 2023 Although several thermal transistors are demonstrated, the use of liquid electrolytes may limit the application from the viewpoint of reliability or liquid leakage. An international team of researchers (Japan, South Korea) constructed and demonstrated a solid-state thermal transistor that can electrochemically control the heat flow with an on-to-off ratio of the thermal conductivity without using any liquid. They constructed thermal transistor on an yttrium oxide-stabilized zirconium oxide base, which also functioned as the switching material, and used strontium cobalt oxide as the active material. Platinum electrodes were used to supply the power required to control the […]
Stretchy, bio-inspired synaptic transistor can enhance, weaken device memories
Science Daily October 3, 2022 A team of researchers in the US (Pennsylvania State University, University of Houston, Northwestern University, industry) has developed a stretchy, wearable synaptic transistor that works like neurons in the brain. They used stretchable bilayer semiconductor materials to fabricate the device, allowing it to stretch and twist while in use unlike the conventional transistors. The transistor is mechanically deformable and functionally reconfigurable, yet still retains its functions when stretched extensively. It can be integrated in robots or wearables and use artificial intelligence to send signals to some cells and inhibit others to enhance and weaken the […]
Researchers create molecule that can pave way for mini transistors
Phys.org February 15, 2022 Organic molecules consist of aromatic benzene rings, flat rings made up of six carbon atoms, which do not change properties or shape if subjected to electric potential. An international team of researchers (Sweden, Denmark) developed a successful formula to design anti-aromatic hydrocarbons made up of rings with eight carbon atoms. When bent into a tub-shape, it becomes more robust and can both receive and relay electrons. If two electrons are injected into it the hydrocarbon flattens and goes from insulating to conducting—a function like that of a transistor switching from 0 to 1. The combination of […]
Nanowires under tension create the basis for ultrafast transistors
Phys.org February 7, 2022 Researchers in Germany produced nanowires consisting of a gallium arsenide core and an indium aluminum arsenide shell. The different chemical ingredients resulted in the crystal structures in the shell and the core having slightly different lattice spacings. This causes the shell to exert a high mechanical strain on the much thinner core changing the electronic properties of gallium arsenide in the core. They demonstrated that the strain in lattice-mismatched core/shell nanowires can affect the effective mass of electrons in a way that boosts their mobility to distinct levels. The electrons inside core of nanowires exhibited mobility […]