Phys.org April 6, 2022 A team of researchers in the US (Princeton University, Sandia National Laboratory) used a two qubits silicon device and forced them to interact. The spin state of each electron can be used as a qubit and the interaction between the electrons can entangle these qubits. To do this they constructed a cage in the form of a wafer-thin semiconductor made primarily out of silicon. At the top of the cage they patterned little electrodes, which create the electrostatic potential used to corral the electron. Two of these cages put together, separated by a barrier, or gate, […]
Tag Archives: Computing
Printing circuits on rare nanomagnets puts a new spin on computing
Phys.org March 28, 2022 An international team of researchers (USA – Argonne National Laboratory, Lawrence Livermore National Laboratory, Switzerland, the Netherlands, Finland) combined theoretical and experimental work to fabricate and observe the artificial spin glass as a proof-of-principle. Hopfield neural network mathematically models associative memory to guide the disorder of the artificial spin systems. They performed temperature-dependent imaging of thermally driven moment fluctuations within these networks and observed characteristic features of a two-dimensional Ising spin glass. They observed clear signatures of the hard-to-observe rugged spin glass free energy in the form of sub-aging, out-of-equilibrium autocorrelations and a transition from stable […]
Crucial leap in error mitigation for quantum computers
Phys.org December 9, 2021 Coherent errors severely limit the performance of quantum algorithms in an unpredictable manner, and mitigating their impact is necessary for realizing reliable quantum computations. The average error rates measured by randomized benchmarking and related protocols are not sensitive to the full impact of coherent errors and therefore do not reliably predict the global performance of quantum algorithms. Randomized compiling is designed to overcome these performance limitations by converting coherent errors into stochastic noise, dramatically reducing unpredictable errors in quantum algorithms, and enabling accurate predictions of algorithmic performance from error rates measured via cycle benchmarking. An international […]
Towards next-gen computers: Mimicking brain functions with graphene-diamond junctions
Science Daily August 4, 2021 Researchers in Japan designed graphene-diamond junctions that can mimic the characteristics of biological synapses and key memory functions, opening the doors for next-generation image sensing memory devices. They demonstrated optoelectronically controlled synaptic functions using junctions between vertically aligned graphene (VG) and diamond. The fabricated junctions mimic biological synaptic functions when stimulated with optical pulses and exhibit other basic brain functions such as the transition from short-term memory (STM) to long-term memory (LTM). The VG-diamond arrays underwent redox reactions induced by fluorescent light and blue LEDs under a bias voltage. The researchers attributed this to the […]
Engineers harvest WiFi signals to power small electronics
Nanowerk May 18, 2021 Widespread use of the 2.4GHz radio frequency that uses WiFi has made excess signals available to be tapped for alternative uses. An international team of researchers (Singapore, India, Japan) has demonstrated electrical synchronization of four non-vortex uniformly magnetized spin-torque oscillators (STOs) using a single common current source in both parallel and series configurations at 2.4 GHz band, resolving the frequency-area quandary for designing STO based on-chip communication systems. The synchronized STOs showed an excellent time-domain stability and substantially improved phase noise performance. By integrating the electrically connected eight STOs, they demonstrated the battery-free energy-harvesting system utilizing the […]
Qubits composed of holes could be the trick to build faster, larger quantum computers
Phys.org April 2, 2021 Strong spin-orbit interactions make hole quantum dots central for scalable quantum computation. Therefore it is important to establish to what extent spin-orbit coupling exposes qubits to electrical noise, facilitating decoherence. Taking Ge as an example an international team of researchers (Australia, Canada) has shown that group IV gate-defined hole spin qubits generically exhibit optimal operation points, defined by the top gate electric field, at which they are both fast and long-lived: the dephasing rate vanishes to first order in the electric field noise along with all directions in space, the electron dipole spin resonance strength is […]
‘Multiplying’ light could be key to ultra-powerful optical computers
EurekAlert February 8, 2021 An international team of researchers (Russia, UK) found that optical systems can combine light by multiplying the wave functions describing the light waves instead of adding them and may represent a different type of connections between the light waves. If the coupling and light intensity is right, the light multiplies, affecting the phases of the individual pulses, giving away the answer to the problem. They found that there is no need to project the continuous light phases onto ‘0’ and ‘1’ states necessary for solving problems in binary variables. Instead, the system tends to bring about […]
Integrated circuit of pure magnons
Nanowerk October 20, 2020 Magnons have been used to encode information in computing applications, and magnonic device components, including logic gates, transistors, and units for non-Boolean computing. Magnonic directional couplers, which can function as circuit building blocks have been impractical because of their millimetre dimensions and multimode spectra. An international team of researchers (Austria, Ukraine, Germany, Belgium, the Netherlands) has developed a magnonic directional coupler based on yttrium iron garnet that has submicrometre dimensions. The coupler consists of single-mode waveguides with a width of 350 nm. They used the amplitude of a spin wave to encode information and to guide it […]
Toward more efficient computing, with magnetic waves
MIT News November 28, 2019 Classical computers rely on massive amounts of electricity for computing and data storage and generate a lot of wasted heat. MIT researchers developed a circuit architecture that uses only a nanometer-wide domain wall in layered nanofilms of magnetic material to modulate a passing spin wave without any extra components or electrical current. In turn, the spin wave can be tuned to control the location of the wall, as needed. This provides precise control of two changing spin wave states, which correspond to the 1s and 0s used in classical computing. In the future, pairs of […]
Engineers using soundwaves to search through big data with more stability and ease
Phys.org September 19, 2019 Using three aluminum rods, enough epoxy to connect them and some rubber bands for elasticity researchers at the University of Arizona have demonstrated the possibility for acoustic waves in a classical environment to do the work of quantum information processing without the time limitations and fragility. They sent a wave of sound vibrations down the rods, then monitored two degrees of freedom of the waves: what direction the waves moved down the rods and how the rods moved in relation to one another. To excite the system into a nonseparable state, they identified a frequency at […]