Efficient classical simulation of noisy random quantum circuits in one dimension

Understanding the computational power of noisy intermediate-scale quantum (NISQ) devices is of both fundamental and practical importance to quantum information science. Here, we address the question of whether error-uncorrected noisy quantum computers can provide computational advantage over classical computers. Specifically, we study noisy random circuit sampling in one dimension (or 1D noisy RCS) as a simple model for exploring the effects of noise on the computational power of a noisy quantum device. In particular, we simulate the real-time dynamics of 1D noisy random quantum circuits via matrix product operators (MPOs) and characterize the computational power of the 1D noisy quantum system by using a metric we call MPO entanglement entropy. The latter metric is chosen because it determines the cost of classical MPO simulation. We numerically demonstrate that for the two-qubit gate error rates we considered, there exists a characteristic system size above which adding more qubits does not bring about an exponential growth of the cost of classical MPO simulation of 1D noisy systems. Specifically, we show that above the characteristic system size, there is an optimal circuit depth, independent of the system size, where the MPO entanglement entropy is maximized. Most importantly, the maximum achievable MPO entanglement entropy is bounded by a constant that depends only on the gate error rate, not on the system size. We also provide a heuristic analysis to get the scaling of the maximum achievable MPO entanglement entropy as a function of the gate error rate. The obtained scaling suggests that although the cost of MPO simulation does not increase exponentially in the system size above a certain characteristic system size, it does increase exponentially as the gate error rate decreases, possibly making classical simulation practically not feasible even with state-of-the-art supercomputers.

Analysis of Brawijaya University Academic Information Systems Acceptance on the User Characteristic, System Quality, Support of Top Management and Information Technology, Perceived Usefulness, and Perceived Ease of Use

Sistem Informasi Dosen (SIADO) as an academic information system for Universitas Brawijaya lecturers are not fully optimized and used since many perspectives about the system, such as system quality complaints and it’s not obligated to use by the University leaders even many benefits can be obtained. This research conducted to describe the factors on SIADO’s user acceptance in five variables, namely is user characteristic, system quality, top management & IT support, perceived usefulness, and perceived ease of use, using descriptive statistical analysis. Data collection techniques with offline questionnaire were distributed using paper from 96 Universitas Brawijaya lecturers. Validation and reliability were checked with statistics methods and descriptive statistical analysis is implemented to measure the level of categories on each variable to provide calculation and information based on data centralization and dissemination, and acquired categorized data. The results show that all five variables receive high category on SIADO acceptance, which indicates the user perception all five variables are good to be used as a consideration tool in receiving the actual use of the system.

Comparative Study of Blade Shape Design of Centrifugal Fan Impeller

For a centrifugal fan impeller the blade shape can be defined using two parameters: the blade angle and the blade width. There are different design methods depending on the assumption made on both the blade width and the blade angle. In this paper four design methods are presented: constant blade width and variable blade angle; hyperbolic blade width and variable blade angle; hyperbolic blade width and constant blade angle; linear blade width and variable blade angle. The sequential algorithm for solving the characteristic system of equations, which defines the blade geometry, is implemented in a MATLAB script file, for which principal code lines are explained. In the solving process of the characteristic system of equations for all four design methods considered, different relationships for relative velocity are obtained. The comparative graphical analysis of impeller blades obtained by all of the four design methods, as well as the blade geometry parameters is presented.

Architectural Aesthetics and Mechanical Behavior of Hagia Sophia

Ancient architecture in Europe is one of the most historic and characteristic system in the world. It follows the order of combining structure and aesthetics. Researching in the pendentive used in Hagia Sophia, this paper explores that European ancient architecture is harmonious and unified in both structure and aesthetics.