Approximate quantum gates compiling with self-navigation algorithm

The compiling of quantum gates is crucial for the successful quantum algorithm implementations. The environmental noise as well as the bandwidth of control pulses pose a challenge to precise and fast qubit control, especially in a weakly anharmonic system. In this work, we propose an algorithm to approximately compile single-qubit gates with arbitrary accuracy. Evaluation results show that the overall rotation distance generated by our algorithm is significantly shorter than the commonly used $U3$ gate, then the gate time can be effectively shortened. The requisite number of pulses and the runtime of scheme design scale up as $\mathcal{O}[\mathrm{Log}(1/\epsilon)]$ with very small prefactors, indicating low overhead costs. Moreover, we explore the trade-off between effectiveness and cost, and find a balance point. In short, our work opens a new avenue for efficient quantum algorithm implementations with contemporary quantum technology.Comment: 5 pages, 2 figure

Prognostic Value of the Neo-Immunoscore in Renal Cell Carcinoma

Objective: This study evaluated the prognostic value of the newly-built Immunoscore (neo-Immunoscore) in patients with renal cell carcinoma (RCC).Methods: Eighty-two patients with RCC were enrolled in this study. Their 3- and 5-year survival rates and overall survival (OS) were evaluated. The clinicopathologic data of the 82 patients were collected and analyzed. CD3, CD4, CD8, CD45RO, Foxp3, tumor necrosis factor receptor type II (TNFR2), programmed death ligand-1 (PD-L1), CD68, programmed death-1 (PD-1), cytokeratin (CK), and indoleamine 2,3-dioxygenase (IDO) were separated into two panels and stained using multiplex fluorescent immunohistochemistry methods. An immunologic prediction model of RCC patients, the neo-Immunoscore (neo-IS), was constructed using a Cox regression model. For the prognostic prediction of RCC, the neo-IS with the immunoscore (IS) proposed by the Society for Immunotherapy of Cancer (SITC) were compared by receiver operator characteristic (ROC) curve analysis. Survivals between the neo-ISlow and neo-IShigh groups were analyzed using the Kaplan–Meier method. Multivariate Cox regression survival analysis was applied to analyze independent indicators.Results: The Cox regression model allowed the establishment of a neo-IS based on three features: CD3CT+, CD4+Foxp3+CD45ROCT+, and CD8+PD-1IM+. Compared to that of the IS proposed by the SITC, the neo-IS obtained a better prediction. The 3- and 5-year survival rates in neo-IShigh RCC patients were significantly higher than those in neo-ISlow RCC patients (94.7 vs. 77.4%, P = 0.035 and 94.7 vs. 64.5%, P = 0.002, respectively). The OS in the neo-ISlow group was significantly shorter than that in the neo-IShigh group (73 vs. 97 months, P = 0.000). In comparisons of the neo-IS with clinical pathological factors, we found that the risk stratification and neo-IS were independent factors for the prognosis of patients with RCC. Moreover, the OS rate of neo-IShigh RCC patients with low- and intermediate- risk was higher than that of neo-ISlow patients.Conclusion: The newly-constructed IS model more precisely predicted the survival of patients with RCC and may supplement the prognostic value of risk stratification

Simulation and application of loose tooling forging for heavy grinding roller shaft forgings

The grinding roller shaft is a key part of the grinding roller. It has a step-shaped shaft with different round cross-sections and 1850 mm × 1110 mm rectangular cross-section. If the general method of free forging is used, the upsetting diameter of ingot will reach 2900 mm, and 8400 t hydraulic press current will not be produced so that the loose tooling forging process is to be used. The loose tooling forging process of rectangular flange has been researched by using DEFORM-3D simulation software and establishing a reasonable forging process. The production results reveal that the heavy forgings used as grinding roller shafts can be successfully produced with the present 8400 t capacity hydraulic presses. The eligible forgings have proved the rationality of the technical process

Hybrid noise protection of logical qubits for universal quantum computation

Quantum computers now show the promise of surpassing any possible classical machine. However, errors limit this ability and current machines do not have the ability to implement error correcting codes due to the limited number of qubits and limited control. Therefore, dynamical decoupling (DD) and encodings that limit noise with fewer qubits are more promising. For these reasons, we put forth a model of universal quantum computation that has many advantages over strategies that require a large overhead such as the standard quantum error correcting codes. First, we separate collective noise from individual noises on physical qubits and use a decoherence-free subspace (DFS) that uses just two qubits for its encoding to eliminate collective noise. Second, our bath model is very general as it uses a spin-boson type bath but without any Markovian assumption. Third, we are able to either use a steady global magnetic field or to devise a set of DD pulses that remove much of the remaining noise and commute with the logical operations on the encoded qubit. This allows removal of noise while implementing gate operations. Numerical support is given for this hybrid protection strategy which provides an efficient approach to deal with the decoherence problems in quantum computation and is experimentally viable for several current quantum computing systems. This is emphasized by a recent experiment on superconducting qubits which shows promise for increasing the number of gates that can be implemented reliably with some realistic parameter assumptions.Comment: 6 pages, 3 figure

Movable Fiber-Integrated Hybrid Plasmonic Waveguide on Metal Film

A waveguide structure consisting of a tapered nanofiber on a metal film is proposed and analyzed to support highly localized hybrid plasmonic modes. The hybrid plasmonic mode can be efficiently excited through the in-line tapered fiber based on adiabatic conversion and collected by the same fiber, which is very convenient in the experiment. Due to the ultrasmall mode area of plasmonic mode, the local electromagnetic field is greatly enhanced in this movable waveguide, which is potential for enhanced coherence light emitter interactions, such as waveguide quantum electrodynamics, single emitter spectrum and nonlinear optics

9-(2-Thien­yl)-9H-carbazole

In the title compound, C16H11NS, the dihedral angles between the fused ring system and the pendant thienyl ring are 86.37 (5) and 57.14 (5)°