Using a quantum computer to simulate fermionic systems requires fermion-to-qubit transformations.Usually,lower Pauli weight of transformations means shallower quantum circuits.Therefore,most existing transformations a...Using a quantum computer to simulate fermionic systems requires fermion-to-qubit transformations.Usually,lower Pauli weight of transformations means shallower quantum circuits.Therefore,most existing transformations aim for lower Pauli weight.However,in some cases,the circuit depth depends not only on the Pauli weight but also on the coefficients of the Hamiltonian terms.In order to characterize the circuit depth of these algorithms,we propose a new metric called weighted Pauli weight,which depends on Pauli weight and coefficients of Hamiltonian terms.To achieve smaller weighted Pauli weight,we introduce a novel transformation,Huffman-code-based ternary tree(HTT)transformation,which is built upon the classical Huffman code and tailored to different Hamiltonians.We tested various molecular Hamiltonians and the results show that the weighted Pauli weight of the HTT transformation is smaller than that of commonly used mappings.At the same time,the HTT transformation also maintains a relatively small Pauli weight.The mapping we designed reduces the circuit depth of certain Hamiltonian simulation algorithms,facilitating faster simulation of fermionic systems.展开更多
Elastic metamaterials with unusual elastic properties offer unprecedented ways to modulate the polarization and propagation of elastic waves.However,most of them rely on the resonant structural components,and thus are...Elastic metamaterials with unusual elastic properties offer unprecedented ways to modulate the polarization and propagation of elastic waves.However,most of them rely on the resonant structural components,and thus are frequency-dependent and unchangeable.Here,we present a reconfigurable 2D mechanism-based metamaterial which possesses transformable and frequency-independent elastic properties.Based on the proposed mechanism-based metamaterial,interesting functionalities,such as ternarycoded elastic wave polarizer and programmable refraction,are demonstrated.Particularly,unique ternary-coded polarizers,with 1-trit polarization filtering and 2-trit polarization separating of longitudinal and transverse waves,are first achieved.Then,the strong anisotropy of the proposed metamaterial is harnessed to realize positive-negative bi-refraction,only-positive refraction,and only-negative refraction.Finally,the wave functions with detailed microstructures are numerically verified.展开更多
Fault reconfiguration of shipboard power system is viewed as a typical nonlinear and multi-objective combinatorial optimization problem. A comprehensive reconfiguration model is presented in this paper, in which the r...Fault reconfiguration of shipboard power system is viewed as a typical nonlinear and multi-objective combinatorial optimization problem. A comprehensive reconfiguration model is presented in this paper, in which the restored loads, switch frequency and generator efficiency are taken into account. In this model, analytic hierarchy process(AHP) is proposed to determine the coefficients of these objective functions. Meanwhile, a quantum differential evolution algorithm with triple quantum bit code is proposed. This algorithm aiming at the characteristics of shipboard power system is different from the normal quantum bit representation. The individual polymorphic expression is realized, and the convergence performance can be further enhanced in combination with the global parallel search capacity of differential evolution algorithm and the superposition properties of quantum theory. The local optimum can be avoided by dynamic rotation gate. The validity of algorithm and model is verified by the simulation examples.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2024YFB4504101)the National Nat-ural Science Foundation of China(Grant No.22303022)the Anhui Province Innovation Plan for Science and Technology(Grant No.202423r06050002).
文摘Using a quantum computer to simulate fermionic systems requires fermion-to-qubit transformations.Usually,lower Pauli weight of transformations means shallower quantum circuits.Therefore,most existing transformations aim for lower Pauli weight.However,in some cases,the circuit depth depends not only on the Pauli weight but also on the coefficients of the Hamiltonian terms.In order to characterize the circuit depth of these algorithms,we propose a new metric called weighted Pauli weight,which depends on Pauli weight and coefficients of Hamiltonian terms.To achieve smaller weighted Pauli weight,we introduce a novel transformation,Huffman-code-based ternary tree(HTT)transformation,which is built upon the classical Huffman code and tailored to different Hamiltonians.We tested various molecular Hamiltonians and the results show that the weighted Pauli weight of the HTT transformation is smaller than that of commonly used mappings.At the same time,the HTT transformation also maintains a relatively small Pauli weight.The mapping we designed reduces the circuit depth of certain Hamiltonian simulation algorithms,facilitating faster simulation of fermionic systems.
基金supported by the National Key R&D Program of China(No.2021YFE0110900)the National Natural Science Foundation of China(Nos.U22B2078 and 11991033)。
文摘Elastic metamaterials with unusual elastic properties offer unprecedented ways to modulate the polarization and propagation of elastic waves.However,most of them rely on the resonant structural components,and thus are frequency-dependent and unchangeable.Here,we present a reconfigurable 2D mechanism-based metamaterial which possesses transformable and frequency-independent elastic properties.Based on the proposed mechanism-based metamaterial,interesting functionalities,such as ternarycoded elastic wave polarizer and programmable refraction,are demonstrated.Particularly,unique ternary-coded polarizers,with 1-trit polarization filtering and 2-trit polarization separating of longitudinal and transverse waves,are first achieved.Then,the strong anisotropy of the proposed metamaterial is harnessed to realize positive-negative bi-refraction,only-positive refraction,and only-negative refraction.Finally,the wave functions with detailed microstructures are numerically verified.
基金the National Natural Science Foundation of China(No.51175321)the Innovation Program of Shanghai Municipal Education Commission(No.12ZZ158)
文摘Fault reconfiguration of shipboard power system is viewed as a typical nonlinear and multi-objective combinatorial optimization problem. A comprehensive reconfiguration model is presented in this paper, in which the restored loads, switch frequency and generator efficiency are taken into account. In this model, analytic hierarchy process(AHP) is proposed to determine the coefficients of these objective functions. Meanwhile, a quantum differential evolution algorithm with triple quantum bit code is proposed. This algorithm aiming at the characteristics of shipboard power system is different from the normal quantum bit representation. The individual polymorphic expression is realized, and the convergence performance can be further enhanced in combination with the global parallel search capacity of differential evolution algorithm and the superposition properties of quantum theory. The local optimum can be avoided by dynamic rotation gate. The validity of algorithm and model is verified by the simulation examples.
