Phys.org December 11, 2024 An international team of researchers (USA – Texas Tech University, China, Saudi Arabia, Sweden Japan) applied electric current pulses to a magnetic multilayer stripe composed of [Pt/Co]3/Ru/[Co/Pt]3 and observed skyrmion motion opposite to the current direction. Upon continuous pulsing, a reversal in the particles’ motion direction was noted. Experimental and micromagnetic simulation analyses revealed that skyrmions in the upper and lower ferromagnetic layers of the multilayer system exhibited different helicities, forming a hybrid synthetic ferromagnetic skyrmion. The helicity switch of the hybrid structure accounted for the motion reversal. According to the researchers their study introduces innovative […]
Tag Archives: Computing
Scientists develop novel high-fidelity quantum computing gate
Phys.org November 22, 2024 Striving for higher gate fidelity is crucial not only for enhancing existing noisy intermediate-scale quantum devices, but also for unleashing the potential of fault-tolerant quantum computation through quantum error correction. Researchers in Japan proposed theoretical scheme, the double-transmon coupler (DTC), that aims to achieve both suppressed residual interaction and a fast high-fidelity two-qubit gate simultaneously, particularly for highly detuned qubits. The state-of-the-art fabrication techniques and a model-free pulse-optimization process would enable not only efficient fault-tolerant quantum computing with error correction but also effectively mitigate errors in current noisy intermediate-scale quantum devices. According to the researchers the […]
Nanoscale transistors could enable more efficient electronics
MIT News November 4, 2024 A range of novel transistor concepts have been explored for the development of data-centric computing for energy-efficient electronics that can overcome the fundamental limitations of conventional silicon transistors. However, an approach that can simultaneously offer high drive current and steep slope switching while delivering the necessary scaling in footprint is still lacking. An international team of researchers (USA – MIT, France, Italy) developed scaled vertical-nanowire heterojunction tunnelling transistors that were based on the broken-band GaSb/InAs system. The approach relies on extreme quantum confinement at the tunnelling junction and was based on an interface-pinned energy band […]
Thermal effects in spintronics systematically assessed for first time
Phys.org September 24, 2024 Current-driven antiferromagnetic order switching has implications for next-generation spintronic devices. Some reports have claimed that demagnetization above the Néel temperature due to Joule heating is critical for switching. University of Illinois at Urbana-Champaign presented a systematic method and an analytical model to quantify the thermal contribution due to Joule heating in micro-electronic devices, focusing on current-driven octupole switching in the non-collinear antiferromagnet, Mn3Sn. Their results consistently showed that the critical temperature for switching remained relatively constant above the Néel temperature, while the threshold current density depended on the choice of substrate and the base temperature. They […]
2D silk protein layers on graphene pave the way for advanced microelectronics and computing
Phys.org September 18, 2024 A team of researchers in the US (Pacific Northwest National Laboratory, University of Washington, Lawrence Berkeley National Laboratory, North Carolina State University) developed highly ordered two-dimensional silk fibroin (SF) films grown epitaxially on van der Waals (vdW) substrates. They showed that the films consisted of lamellae of SF molecules that exhibited the same secondary structure as the nanocrystallites of native silk. Increasing the SF concentration resulted in multilayers that grew either by direct assembly of SF molecules into the lamellae or, at high concentrations, along a two-step pathway beginning with a disordered monolayer that crystallizes. They […]
Molecular simulations and supercomputing shed light on energy-saving biomaterials
Phys.org September 6, 2024 Nanocellulose from biomass is promising for manufacturing sustainable composite biomaterials and bioplastics. However, obtaining nanocellulose at pilot scale requires energy-intensive fibrillation to shear cellulose fibers apart into nano-dimensional forms in water. To reduce the energy consumption in fibrillation a team of researchers in the US (Oak Ridge National Laboratory, University of Maine) found that aqueous NaOH:urea (0.007:0.012 wt.%) reduced the fibrillation energy by ~21% on average relative to water alone. The NaOH and urea acted synergistically on CNFs to aid fibrillation but at different length scales. According to the researchers their work suggested a general mechanism […]
New quantum error correction method uses ‘many-hypercube codes’ while exhibiting beautiful geometry
Phys.org September 6, 2024 Standard approaches to quantum error correction for fault-tolerant quantum computing result in asymptotically zero encoding rates and huge resource overheads. Researchers in Japan proposed concatenated high-rate small-size quantum error-detecting codes as a family of high-rate quantum codes. Their structure allowed for a geometrical interpretation using hypercubes corresponding to logical qubits. Using their method of many-hypercube codes they realized both high rates, e.g., 30% (64 logical qubits are encoded into 216 physical ones), and parallelizability of logical gates. Developing dedicated decoder and encoders, achieved high error thresholds even in a circuit-level noise model. According to the researchers […]
Physicists propose time crystal-based circuit board to reduce quantum computing errors
Phys.org June 21, 2024 Time crystalline structures, which can reveal different condensed matter behaviors, can be created in periodically driven systems. However, the potential practical applications of time crystalline structures have yet to be explored. An international team of researchers (Poland, Australia) paved the way for timetronics where temporal lattices were like printed circuit boards for realization of a broad range of quantum devices. The elements of these devices corresponded to structures of dimensions higher than three and could be arbitrarily connected and reconfigured at any moment. Their approach allowed for the construction of a quantum computer, enabling quantum gate […]
The experimental demonstration of a verifiable blind quantum computing protocol
Phys.org April 13, 2024 An international team of researchers (UK, France, USA -University of Maryland) used a trapped-ion quantum server and a client-side photonic detection system networked via a fiber-optic quantum link. The availability of memory qubits and deterministic entangling gates enabled interactive protocols without post selection which previous realizations could not provide. They quantified the privacy at ≲0.03 leaked classical bits per qubit. According to the researchers their experiment demonstrated a path to fully verified quantum computing in the cloud… read more. Open Access TECHNICAL ARTICLE
Researchers achieve breakthrough in silicon-compatible magnetic whirls
Phys.org February 20, 2024 Antiferromagnets hosting real-space topological textures are promising platforms to model fundamental ultrafast phenomena and explore spintronics. However, as they are epitaxially fabricated on specific symmetry-matched substrates, preserving their intrinsic magneto-crystalline order, curtails their integration with dissimilar supports, restricting the scope of fundamental and applied investigations. An international team of researchers (UK, Switzerland, Singapore) circumvented this limitation by designing detachable crystalline antiferromagnetic nanomembranes of α-Fe2O3. They showed that flat nanomembranes host a spin-reorientation transition and rich topological phenomenology. They demonstrated the reconfiguration of antiferromagnetic states across three-dimensional membrane folds resulting from flexure-induced strains. They combined these developments […]