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Modulation of Quantum Features of a Driven Two-Level System via a rf Field Cover

Modulation of Quantum Features of a Driven Two-Level System via a rf Field

Quantum Information & Computation
Volume 25 (2025): Issue 3 (June 2025)
By: Shuning Sun,  Xiangjia Meng and  Xiangji Cai  
Open Access
|Jul 2025

Figures & Tables

Figure 1.

Line shapes of the coherence norm 𝒞(ρ) = ∑i≠j |ρij| (ρij is the matrix elements under a specific basis) as functions of the scaled evolution time Γt. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(denoted in sold red line), ξ = 2(denoted in the ‘+’ marked cyan line), ξ = 4(denoted in the ‘○’ marked yellow line) and ξ = 6(denoted in dashed green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.
Line shapes of the coherence norm 𝒞(ρ) = ∑i≠j |ρij| (ρij is the matrix elements under a specific basis) as functions of the scaled evolution time Γt. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(denoted in sold red line), ξ = 2(denoted in the ‘+’ marked cyan line), ξ = 4(denoted in the ‘○’ marked yellow line) and ξ = 6(denoted in dashed green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.

Figure 2.

Line shapes of the fidelity Fb as functions of the scaled evolution time Γt. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘○’ marked green line). The ground state is chosen as the initial state 𝒲(0) = −1/2.
Line shapes of the fidelity Fb as functions of the scaled evolution time Γt. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘○’ marked green line). The ground state is chosen as the initial state 𝒲(0) = −1/2.

Figure 3.

The length of geodesic ℒ as functions of the scaled evolution time Γt under varied rf field modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘⚬’ marked green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.
The length of geodesic ℒ as functions of the scaled evolution time Γt under varied rf field modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘⚬’ marked green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.

Figure 4.

(a) The length of the geodesic ℒ as functions of Γt under varied rf field modulation index ξ. Γt ranges from 0 to τξ. τξ is determined by the the first time for ℒ reaches the maximum value ℒmax. (b) The maximum evolution speed υQSL as functions of Γt under varied rf field modulation index ξ. (c) τQSL / τ as functions of Γt under varied rf field modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘⚬’ marked green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.
(a) The length of the geodesic ℒ as functions of Γt under varied rf field modulation index ξ. Γt ranges from 0 to τξ. τξ is determined by the the first time for ℒ reaches the maximum value ℒmax. (b) The maximum evolution speed υQSL as functions of Γt under varied rf field modulation index ξ. (c) τQSL / τ as functions of Γt under varied rf field modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. ξ = 0(the solid blue line), ξ = 4(the ‘×’ marked red line) and ξ = 8(the ‘⚬’ marked green line). The ground state is chosen as the initial state 𝒲(0) = –1/2.

Figure 5.

The τQSL / τ as function of the rf modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. The ground state is chosen as the initial state 𝒲(0) = –1/2.
The τQSL / τ as function of the rf modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. The ground state is chosen as the initial state 𝒲(0) = –1/2.

Figure 6.

The fidelity Fb between the evolved density matrix ρτξ and the initial density matrix ρ0 as function of the rf modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. The ground state is chosen as the initial state 𝒲(0) = –1/2.
The fidelity Fb between the evolved density matrix ρτξ and the initial density matrix ρ0 as function of the rf modulation index ξ. Parameters used include, Ω = Γ, ωrf = 0.5Γ, δL = 0 and Γ = 20 MHz. The ground state is chosen as the initial state 𝒲(0) = –1/2.
DOI: https://doi.org/10.2478/qic-2025-0013 | Journal eISSN: 3106-0544 | Journal ISSN: 1533-7146
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Language: English
Page range: 248 - 259
Submitted on: Nov 3, 2024
Accepted on: Mar 23, 2025
Published on: Jul 1, 2025
Published by: Cerebration Science Publishing Co., Limited
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Keywords:
coherence,
fidelity,
quantum speed limit
Related subjects:
Physics,
Quantum physics

© 2025 Shuning Sun, Xiangjia Meng, Xiangji Cai, published by Cerebration Science Publishing Co., Limited
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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