Donor spin systems host a native Hilbert space whose dimension exceeds that of a qubit, meaning they can be used as qudits. Here we study a \ce{Si{:}P} donor spin system through leakage-aware randomized benchmarking (RB) of native ququart $\mathcal{C}_4$ and encoded two-qubit $\mathcal{C}_2^{\otimes 2}$ Clifford groups. We implement adiabatic ramps to operate electron dipole spin resonance (EDSR) pulses at the ionization point, where the electron is shared halfway between the donor and the interface, and to operate electron spin resonance (ESR) pulses near the interface, motivated by the sensitivity of the effective magnetic field to charge noise at the ionization point. By placing the electron near the ionization point only during EDSR control and using sufficiently long displacement ramp durations, leakage outside the computational basis is strongly suppressed, which is crucial for optimized qudit control. We find in our analysis based on leakage RB that $\mathcal{C}_4$ consistently achieves $\sim 40$ -- $50\%$ lower (lower-bound) error rates $\varepsilon^{\mathrm{LB}}_\mathrm{PT}$ with respect to $\mathcal{C}_2^{\otimes 2}$ , due to its reduced circuit complexity. These results indicate that donor spin qudits benefit from genuine qudit operation as opposed to imposed encoded qubit operation.Donor spin systems host a native Hilbert space whose dimension exceeds that of a qubit, meaning they can be used as qudits. Here we study a \ce{Si{:}P} donor spin system through leakage-aware randomized benchmarking (RB) of native ququart $\mathcal{C}_4$ and encoded two-qubit $\mathcal{C}_2^{\otimes 2}$ Clifford groups. We implement adiabatic ramps to operate electron dipole spin resonance (EDSR) pulses at the ionization point, where the electron is shared halfway between the donor and the interface, and to operate electron spin resonance (ESR) pulses near the interface, motivated by the sensitivity of the effective magnetic field to charge noise at the ionization point. By placing the electron near the ionization point only during EDSR control and using sufficiently long displacement ramp durations, leakage outside the computational basis is strongly suppressed, which is crucial for optimized qudit control. We find in our analysis based on leakage RB that $\mathcal{C}_4$ consistently achieves $\sim 40$--$50\%$ lower (lower-bound) error rates $\varepsilon^{\mathrm{LB}}_\mathrm{PT}$ with respect to $\mathcal{C}_2^{\otimes 2}$, due to its reduced circuit complexity. These results indicate that donor spin qudits benefit from genuine qudit operation as opposed to imposed encoded qubit operation.

quant-pharXiv:2607.07586Jul 9, 20260 citations

Randomized Benchmarking of Quantum Gates on a GPU

Syed Zawad, Feng Yan, Rui Wu +2 more

Advances in intelligent systems and computingJan 1, 20190 citations

Benchmarking a Spin-Based Quantum Computer

Marric Stephens

PhysicsJan 14, 20260 citations

Resonantly driven CNOT gate for electron spins

D. M. Zajac, Anthony J. Sigillito, Maximilian Rimbach-Russ +4 more

Single-qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. Although high-fidelity single-qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been challenging because of rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly driven CNOT gate for electron spins in silicon. Our platform achieves single-qubit rotations with fidelities greater than 99%, as verified by randomized benchmarking. Gate control of the exchange coupling allows a quantum CNOT gate to be implemented with resonant driving in ~200 nanoseconds. We used the CNOT gate to generate a Bell state with 78% fidelity (corrected for errors in state preparation and measurement). Our quantum dot device architecture enables multi-qubit algorithms in silicon.Single-qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. Although high-fidelity single-qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been challenging because of rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly driven CNOT gate for electron spins in silicon. Our platform achieves single-qubit rotations with fidelities greater than 99%, as verified by randomized benchmarking. Gate control of the exchange coupling allows a quantum CNOT gate to be implemented with resonant driving in ~200 nanoseconds. We used the CNOT gate to generate a Bell state with 78% fidelity (corrected for errors in state preparation and measurement). Our quantum dot device architecture enables multi-qubit algorithms in silicon.

arXiv:1708.03530ScienceDec 7, 2017561 citations

QUANTUM LOGICAL GATE BASED ON ELECTRON SPIN RESONANCE

Masanori Ohya, Igor Vasil'evich Volovich, Noboru Watanabe

May 1, 20011 citation

On an Electron Spin Resonance Spectrometer for Quantum Information Processing

Jeremy Chamilliard

Electron spins are an attractive candidate for an implementation of quantum information processing (QIP) due to high polarization, fast control and long coherence times. Control in electron spin resonance beneﬁts from extensive experience in liquid-state nuclear magnetic resonance QIP, and microwave and RF technology from industry. This thesis details the design and construction of an electron spin resonance spectrometer speciﬁcally for research in quantum information processing, including the microwave electronics and variable temperature resonators and probes. We also begin to evaluate our spectrometer using a novel technique known as randomized benchmarking which extracts a ﬁgure of merit relevant to QIP.Electron spins are an attractive candidate for an implementation of quantum information processing (QIP) due to high polarization, fast control and long coherence times. Control in electron spin resonance beneﬁts from extensive experience in liquid-state nuclear magnetic resonance QIP, and microwave and RF technology from industry. This thesis details the design and construction of an electron spin resonance spectrometer speciﬁcally for research in quantum information processing, including the microwave electronics and variable temperature resonators and probes. We also begin to evaluate our spectrometer using a novel technique known as randomized benchmarking which extracts a ﬁgure of merit relevant to QIP.

Jan 24, 20114 citations

\mathcal{C}_4

and encoded two-qubit

\mathcal{C}_2^{\otimes 2}

Clifford groups. We implement adiabatic ramps to operate electron dipole spin resonance (EDSR) pulses at the ionization point, where the electron is shared halfway between the donor and the interface, and to operate electron spin resonance (ESR) pulses near the interface, motivated by the sensitivity of the effective magnetic field to charge noise at the ionization point. By placing the electron near the ionization point only during EDSR control and using sufficiently long displacement ramp durations, leakage outside the computational basis is strongly suppressed, which is crucial for optimized qudit control. We find in our analysis based on leakage RB that

\mathcal{C}_4

consistently achieves

\sim 40

50\%

lower (lower-bound) error rates

\varepsilon^{\mathrm{LB}}_\mathrm{PT}

with respect to

\mathcal{C}_2^{\otimes 2}

, due to its reduced circuit complexity. These results indicate that donor spin qudits benefit from genuine qudit operation as opposed to imposed encoded qubit operation.