Phys.org December 5, 2024 Strong coupling between polarization (P) and strain (ɛ) in ferroelectric complex oxides offers unique opportunities to dramatically tune their properties. An international team of researchers (USA – Pennsylvania State University, Cornell University, Stanford University, University of Nebraska, Argonne National Laboratory, Belgium, Germany) demonstrated strain tuning of ferroelectricity in epitaxial potassium niobate (KNbO3) thin films grown by sub-oxide molecular beam epitaxy. While bulk KNbO3 exhibited three ferroelectric transitions and a Curie temperature (Tc) of ≈676 K, phase-field modeling predicted that a biaxial strain pushes its Tc > 975 K, its decomposition temperature in air, and for −1.4% […]
Category Archives: Quantum computing
Tuning skyrmion helicity for racetrack memory and quantum computing applications
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 […]
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 […]
In step forward for quantum computing hardware, IU physicist uncovers novel behavior in quantum-driven superconductors
EurekAlert November 12, 2024 An international team of researchers (India, USA – Indiana University) studied the transport signatures of unpaired Floquet Majorana fermions in the Josephson current of weakly linked, periodically driven topological superconductors. They obtained analytical expressions for the occupation of the Floquet Majorana fermions in the presence of weak coupling to thermal reservoirs, and showed that, similar to undriven topological superconductors, for sufficiently low temperatures and large systems the Josephson current involving Floquet Majorana fermions is in the phase difference across the junction and depends linearly on the coupling between superconductors. Unlike the static case, the amplitude of […]
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 […]
Higher-order topological simulation unlocks new potential in quantum computers
Phys. org August 30, 2024 At present the range of viable applications with noisy intermediate-scale quantum (NISQ) devices remains limited by gate errors and the number of high-quality qubits. An international team of researchers (USA – Caltech, MIT, Singapore) developed an approach that places digital NISQ hardware as a versatile platform for simulating multi-dimensional condensed matter systems. Their method encoded a high-dimensional lattice in terms of many-body interactions on a reduced-dimension model, thereby taking full advantage of the exponentially large Hilbert space of the host quantum system. With circuit optimization and error mitigation techniques, they measured the topological state dynamics […]
Manipulation of nanolight provides new insight for quantum computing and thermal management
Phys.org August 26, 2024 Anisotropic planar polaritons – hybrid electromagnetic modes mediated by phonons, plasmons, or excitons – in biaxial two-dimensional (2D) van der Waals crystals have attracted significant attention due to their fundamental physics and potential nanophotonic applications. An international team of researchers (USA – University of Minnesota, Auburn University, Purdue University, City University of New York, IBM T. J. Watson Research Center, Vanderbilt University, Republic of Korea, Spain) reviewed the properties of planar hyperbolic polaritons and methods that could be used to experimentally tune them. They argued that such natural, planar hyperbolic media should be common in biaxial […]
Layered superconductor coaxed to show unusual properties with potential for quantum computing
Phys.org July 31, 2024 Chiral superconductors are a unique class of unconventional superconductors in which the complex superconducting order parameter winds clockwise or anticlockwise in the momentum space. It represents a topologically non-trivial system with intrinsic time-reversal symmetry breaking (TRSB) and direct implications for topological quantum computing. Chiral molecules with neither mirror nor inversion symmetry have been widely investigated. An international team of researchers (USA – UCLA, Czech Republic) explored unconventional superconductivity in chiral molecule intercalated TaS2 hybrid superlattices. The experimental signatures of unconventional superconductivity suggested that the intriguing interplay between crystalline atomic layers and the self-assembled chiral molecular layers […]
Optical fibers fit for the age of quantum computing
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 […]
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 […]