We study two flux qubits with a parameter coupling scenario. Under the rotating wave approximation, we truncate the 4-dimensional Hilbert space of a coupling flux qubits system to a 2-dimensional subspace spanned by t...We study two flux qubits with a parameter coupling scenario. Under the rotating wave approximation, we truncate the 4-dimensional Hilbert space of a coupling flux qubits system to a 2-dimensional subspace spanned by two dressed states ｜01} and ｜10}. In this subspace, we illustrate how to generate an Aharnov Anandan phase, based on which, we can construct a NOT gate （as effective as a C-NOT gate） in this coupling flux qubits system. FinMly, the fidelity of the NOT gate is also calculated in the presence of the simulated classical noise.展开更多
The well-known physicist Chen Ning Yang[1]once summarized that the three main themes of 20th-century physics are quantization,the phase factor,and symmetry.Phase,as a fundamental characteristic of quantum mechanics,se...The well-known physicist Chen Ning Yang[1]once summarized that the three main themes of 20th-century physics are quantization,the phase factor,and symmetry.Phase,as a fundamental characteristic of quantum mechanics,serves as the cornerstone for all interference phenomena.In 1984,Berry pointed out that when the parameters in the Hamiltonian evolve slowly enough(adiabatically)to return to their original values,the wave function of a two-level system acquires a pure geometric phase factor,known as the Berry phase[2].This phase factor is precisely the holonomy in a Hermitian line bundle[3].In 1987,Aharonov and Anandan[4]further discovered that,in non-adiabatic conditions,there exists a geometric phase factor known as the A-A phase,arising in a process called cyclic evolution,which can be regarded as a non-adiabatic generalization of the Berry phase.展开更多
Ⅰ. INTRODUCTION Since Berry’s discovery of the geometric phase in quantum adiabatic evolution, there has been increased interest in this holonomy phenomenon referred to as Berry phase. Aharonov and Anandan removed t...Ⅰ. INTRODUCTION Since Berry’s discovery of the geometric phase in quantum adiabatic evolution, there has been increased interest in this holonomy phenomenon referred to as Berry phase. Aharonov and Anandan removed the adiabatic condition and studied the geometric phase (AA phase) for any cyclic evolution. AA phase and Berry phase have been verified in展开更多
A new method to construct coherent states of a time-dependent forced harmonic oscillator was given. The close relation to the classical forced oscillator and the minimum uncertainty relation were investigated. The app...A new method to construct coherent states of a time-dependent forced harmonic oscillator was given. The close relation to the classical forced oscillator and the minimum uncertainty relation were investigated. The applied periodic force (off-resonance case), in general, will attenuate the AA phase.展开更多
基金Project supported by the National Basic Research Program of China (Grant Nos. 2011CBA00106 and 2009CB929102)the National Natural Science Foundation of China (Grant Nos. 11161130519 and 10974243)the Fundamental Research Funds for the Central Universities, China (Grant No. CDJXS11100012)
文摘We study two flux qubits with a parameter coupling scenario. Under the rotating wave approximation, we truncate the 4-dimensional Hilbert space of a coupling flux qubits system to a 2-dimensional subspace spanned by two dressed states ｜01} and ｜10}. In this subspace, we illustrate how to generate an Aharnov Anandan phase, based on which, we can construct a NOT gate （as effective as a C-NOT gate） in this coupling flux qubits system. FinMly, the fidelity of the NOT gate is also calculated in the presence of the simulated classical noise.
基金the National Key Research and Development Program of China(2022YFA1405100)the National Natural Science Foundation of China(12241405,12174384,and 12404146)。
文摘The well-known physicist Chen Ning Yang[1]once summarized that the three main themes of 20th-century physics are quantization,the phase factor,and symmetry.Phase,as a fundamental characteristic of quantum mechanics,serves as the cornerstone for all interference phenomena.In 1984,Berry pointed out that when the parameters in the Hamiltonian evolve slowly enough(adiabatically)to return to their original values,the wave function of a two-level system acquires a pure geometric phase factor,known as the Berry phase[2].This phase factor is precisely the holonomy in a Hermitian line bundle[3].In 1987,Aharonov and Anandan[4]further discovered that,in non-adiabatic conditions,there exists a geometric phase factor known as the A-A phase,arising in a process called cyclic evolution,which can be regarded as a non-adiabatic generalization of the Berry phase.
基金Project supported by the Foundation for Ph. D. Training Programme of China and Zhejiang Provincial Natural Science Foundation of China
文摘Ⅰ. INTRODUCTION Since Berry’s discovery of the geometric phase in quantum adiabatic evolution, there has been increased interest in this holonomy phenomenon referred to as Berry phase. Aharonov and Anandan removed the adiabatic condition and studied the geometric phase (AA phase) for any cyclic evolution. AA phase and Berry phase have been verified in
文摘A new method to construct coherent states of a time-dependent forced harmonic oscillator was given. The close relation to the classical forced oscillator and the minimum uncertainty relation were investigated. The applied periodic force (off-resonance case), in general, will attenuate the AA phase.
