Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Semiconductor Physics Quantum Electronics & Optoelectronics

Fidelity of noisy multiple-control reversible gates

V. G. Deı̆buk, Ivan Yuriychuk, Igor Lemberski

Published Nov 19, 2020• 3 citations
Publisher

Abstract

The effect of frequency noise on correct operation of the multiple-control Toffoli, Fredkin, and Peres gates has been discussed. In the framework of the Ising model, the energy spectrum of a chain of atoms with nuclear spins one-half in a spinless semiconductor matrix has been obtained, and allowed transitions corresponding to the operation algorithm of these gates have been determined. The fidelities of the obtained transitions were studied depending on the number of control qubits and parameters of the radio-frequency control pulses. It has been shown that correct operation of the Toffoli and Fredkin gates does not depend on the number of control qubits, while the Peres gate fidelity decreases significantly with the increasing number of control signals. The calculated ratios of the Larmor frequency to the exchange interaction constant correspond with the results of other studies.

DOI
10.15407/spqeo23.04.385

Related papers

Noisy Multiple-Control Fredkin Gate in Nuclear Spin Based Qubits Chain

V. G. Deı̆buk, Ivan Yuriychuk

The Fredkin gate is a reversible self-inverse logic gate that maintains parity, so it is widely used in DNA computing, low-power CMOS, quantum computing, and nanotechnology. The paper proposes a design of the multiple-control Fredkin gate based on the model of a chain of atoms with nuclear spins one-half in a spinless semiconductor matrix. The allowed transitions realizing the gate operation for two π-pulses are analyzed. The effect of frequency noise and decoherence on the fidelity of the multiple-control Fredkin gate are discussed.

IEEE International Conference on Data Stream Mining & Processing (DSMP)•Aug 1, 2020•3 citations

Effects on the quantum not and controlled-not gates of a modular magnetic field in the z-direction in a chain of nuclear spin system

Gustavo V. López, Manuél Ávila

We study the simulation of a single qubit rotation and Controlled-Not gate in a solid state one-dimensional chain of nuclear spins system interacting weakly through an Ising type of interaction with a modular component of the magnetic field in the z-direction, characterized by Bz (z,t) = Bo(z) cos dt. These qubits are subjected to electromagnetic pulses which determine the transition in the one or two qubits system. We use the fidelity parameter to determine the performance of the Not (N) gate and Controlled-Not (CNOT) gate as a function of the frequency parameter S. We found that for |d| 10-3 MHz, these gates still have good fidelity.

Revista Mexicana de Física•Aug 15, 2011•0 citations

Modular magnetic field on the z-direction on a chain of nuclear spin system and quantum Not and Controlled-Not gates

Gustavo V. López, Manuél Ávila

We study the simulation of a single qubit rotation and Controlled-Not gate in a solid state one-dimensional chain of nuclear spins system interacting weakly through an Ising type of interaction with a modular component of the magnetic field in the z-direction, characterized by $B_z(z,t)=Bo(z)\cosδt$. These qubits are subjected to electromagnetic pulses which determine the transition in the one or two qubits system. We use the fidelity parameter to determine the performance of the Not (N) gate and Controlled-Not (CNOT) gate as a function of the frequency parameter $δ$. We found that for $|δ|\le 10^{-3} MHz$, these gates still have good fidelity.

arXiv:1205.6449•Mar 2, 2012•0 citations

Modeling and Experimental Validation of the Intrinsic SNR in Spin Qubit Gate-Based Readout and Its Impacts on Readout Electronics

Bagas Prabowo, Jurgen Dijkema, Xiao Xue +3 more

In semiconductor spin quantum bits (qubits), the radio-frequency (RF) gate-based readout is a promising solution for future large-scale integration, as it allows for a fast, frequency-multiplexed readout architecture, enabling multiple qubits to be read out simultaneously. This paper introduces a theoretical framework to evaluate the effect of various parameters, such as the readout probe power, readout chain's noise performance, and integration time on the intrinsic readout signal-to-noise ratio (SNR), and thus readout fidelity of RF gate-based readout systems. By analyzing the underlying physics of spin qubits during readout, this work proposes a qubit readout model that takes into account the qubit's quantum mechanical properties, providing a way to evaluate the trade-offs among the aforementioned parameters. The validity of the proposed model is evaluated by comparing the simulation and experimental results. The proposed analytical approach, the developed model, and the experimental results enable designers to optimize the entire readout chain effectively, thus leading to a faster, lower-power readout system with integrated cryogenic electronics.

arXiv:2312.08993•IEEE Transactions on Quantum Engineering•Jan 1, 2024•6 citations

Optimal Control for Rydberg multi-qubit operations

Hossein Abedi, Mohammadsadegh Khazali, Klaus Mølmer

Quantum computing algorithms can be decomposed into a universal set of elementary one- and two-qubit gates. Different physical implementations of quantum computing, however, employ interactions that permit direct conditional dynamics on multiple qubits in a single step. In this work, we leverage quantum optimal control techniques to design single continuous laser pulses that implement multi-qubit controlled-phase, -NOT and -swap (Fredkin) gates on Rydberg atom quantum processors. The identification of robust multi-qubit operations leads to reduced operation time and less decoherence, and the control field provides continuous protection of the atoms from environmental noise. Notably, we find that the controlled-swap (Fredkin) gate, implemented using this approach achieves 99.74\% fidelity while accounting for imperfections such as spontaneous emission, laser fluctuations, and Doppler dephasing.

quant-pharXiv:2511.22202•Nov 28, 2025•0 citations

Simulation of temperature-dependent quantum gates in silicon quantum dots with frequency shifts

Yudai Sato, T. Kawahara

To achieve quantum computing using semiconductor spin qubits, the spin qubits must be precisely controlled. However, unexpected noise limits this precision and prevents the implementation of error correction codes. Specifically, frequency shifts have been found to suppress one-qubit gate fidelity. Although the exact source of the frequency shifts remains unclear, several experiments have indicated a relationship between the frequency shift and heating from the control signal. Based on these results, we modeled the heating effect using the low-temperature dependence of specific heat from the Debye model to simulate qubit control with frequency shifts. This model quantitatively reproduces some of the experimental results and makes it possible to simulate qubit gates with temperature-dependent frequency shifts. The simulated control fidelity of the proposed model was consistent with the experimental results, demonstrating that a gate fidelity above $99.9$% can be achieved in a hot environment. Additionally, our comparison of the two temperature-dependent frequency shift models reveals the condition for a microscopic frequency shift model in which the variance of the frequency shift is limited to a specific range. Furthermore, we investigated gate fidelity using the DRAG method and demonstrated the utility of temperature-dependent simulations.

arXiv:2407.05295•Jul 7, 2024•0 citations
The effect of frequency noise on correct operation of the multiple-control Toffoli, Fredkin, and Peres gates has been discussed. In the framework of the Ising model, the energy spectrum of a chain of atoms with nuclear spins one-half in a spinless semiconductor matrix has been obtained, and allowed transitions corresponding to the operation algorithm of these gates have been determined. The fidelities of the obtained transitions were studied depending on the number of control qubits and parameters of the radio-frequency control pulses. It has been shown that correct operation of the Toffoli and Fredkin gates does not depend on the number of control qubits, while the Peres gate fidelity decreases significantly with the increasing number of control signals. The calculated ratios of the Larmor frequency to the exchange interaction constant correspond with the results of other studies.
The Fredkin gate is a reversible self-inverse logic gate that maintains parity, so it is widely used in DNA computing, low-power CMOS, quantum computing, and nanotechnology. The paper proposes a design of the multiple-control Fredkin gate based on the model of a chain of atoms with nuclear spins one-half in a spinless semiconductor matrix. The allowed transitions realizing the gate operation for two π-pulses are analyzed. The effect of frequency noise and decoherence on the fidelity of the multiple-control Fredkin gate are discussed.
We study the simulation of a single qubit rotation and Controlled-Not gate in a solid state one-dimensional chain of nuclear spins system interacting weakly through an Ising type of interaction with a modular component of the magnetic field in the z-direction, characterized by Bz (z,t) = Bo(z) cos dt. These qubits are subjected to electromagnetic pulses which determine the transition in the one or two qubits system. We use the fidelity parameter to determine the performance of the Not (N) gate and Controlled-Not (CNOT) gate as a function of the frequency parameter S. We found that for |d| 10-3 MHz, these gates still have good fidelity.
We study the simulation of a single qubit rotation and Controlled-Not gate in a solid state one-dimensional chain of nuclear spins system interacting weakly through an Ising type of interaction with a modular component of the magnetic field in the z-direction, characterized by Bz(z,t)=Bo(z)cos⁡δtB_z(z,t)=Bo(z)\cosδtBz​(z,t)=Bo(z)cosδt. These qubits are subjected to electromagnetic pulses which determine the transition in the one or two qubits system. We use the fidelity parameter to determine the performance of the Not (N) gate and Controlled-Not (CNOT) gate as a function of the frequency parameter δδδ. We found that for ∣δ∣≤10−3MHz|δ|\le 10^{-3} MHz∣δ∣≤10−3MHz, these gates still have good fidelity.
In semiconductor spin quantum bits (qubits), the radio-frequency (RF) gate-based readout is a promising solution for future large-scale integration, as it allows for a fast, frequency-multiplexed readout architecture, enabling multiple qubits to be read out simultaneously. This paper introduces a theoretical framework to evaluate the effect of various parameters, such as the readout probe power, readout chain's noise performance, and integration time on the intrinsic readout signal-to-noise ratio (SNR), and thus readout fidelity of RF gate-based readout systems. By analyzing the underlying physics of spin qubits during readout, this work proposes a qubit readout model that takes into account the qubit's quantum mechanical properties, providing a way to evaluate the trade-offs among the aforementioned parameters. The validity of the proposed model is evaluated by comparing the simulation and experimental results. The proposed analytical approach, the developed model, and the experimental results enable designers to optimize the entire readout chain effectively, thus leading to a faster, lower-power readout system with integrated cryogenic electronics.
Quantum computing algorithms can be decomposed into a universal set of elementary one- and two-qubit gates. Different physical implementations of quantum computing, however, employ interactions that permit direct conditional dynamics on multiple qubits in a single step. In this work, we leverage quantum optimal control techniques to design single continuous laser pulses that implement multi-qubit controlled-phase, -NOT and -swap (Fredkin) gates on Rydberg atom quantum processors. The identification of robust multi-qubit operations leads to reduced operation time and less decoherence, and the control field provides continuous protection of the atoms from environmental noise. Notably, we find that the controlled-swap (Fredkin) gate, implemented using this approach achieves 99.74\% fidelity while accounting for imperfections such as spontaneous emission, laser fluctuations, and Doppler dephasing.
To achieve quantum computing using semiconductor spin qubits, the spin qubits must be precisely controlled. However, unexpected noise limits this precision and prevents the implementation of error correction codes. Specifically, frequency shifts have been found to suppress one-qubit gate fidelity. Although the exact source of the frequency shifts remains unclear, several experiments have indicated a relationship between the frequency shift and heating from the control signal. Based on these results, we modeled the heating effect using the low-temperature dependence of specific heat from the Debye model to simulate qubit control with frequency shifts. This model quantitatively reproduces some of the experimental results and makes it possible to simulate qubit gates with temperature-dependent frequency shifts. The simulated control fidelity of the proposed model was consistent with the experimental results, demonstrating that a gate fidelity above 99.999.999.9% can be achieved in a hot environment. Additionally, our comparison of the two temperature-dependent frequency shift models reveals the condition for a microscopic frequency shift model in which the variance of the frequency shift is limited to a specific range. Furthermore, we investigated gate fidelity using the DRAG method and demonstrated the utility of temperature-dependent simulations.