Tin as a nuclear spin qubit in silicon

Wayne M. Witzel

Published Mar 1, 2024• 0 citations

Publisher

Abstract

for single-qubit Clifford gates Micromagnet Array of 6 Loss-DiVincenzo qubits Combining nuclear and electron qubits 5

DOI: 10.2172/2540383

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Tin as a nuclear spin qubit in silicon.

Wayne M. Witzel, Dwight Luhman, Jesse J. Lutz +7 more

Aug 1, 20220 citations

Micromagnet-free operation of electron spin qubits in Si/Si$_{1-x}$Ge$_x$ vertical double quantum dots

Abhikbrata Sarkar, Daniel Loss

cond-mat.mes-hallCross-listedarXiv:2512.19785Dec 24, 2025

High-fidelity initialization and control of electron and nuclear spins in a four-qubit register

Jan-Michael Reiner, Yousun Chung, S. H. Misha +15 more

Abstract Single electron spins bound to multi-phosphorus nuclear spin registers in silicon have demonstrated fast (0.8 ns) two-qubit $$\sqrt{\mathrm{SWAP}}$$ SWAP gates and long spin relaxation times (~30 s). In these spin registers, when the donors are ionized, the nuclear spins remain weakly coupled to their environment, allowing exceptionally long coherence times. When the electron is present, the hyperfine interaction allows coupling of the spin and charge degrees of freedom for fast qubit operation and control. Here we demonstrate the use of the hyperfine interaction to enact electric dipole spin resonance to realize high-fidelity ( $$F=10{0}_{-6}^{+0}$$ F = 10 0 − 6 + 0 %) initialization of all the nuclear spins within a four-qubit nuclear spin register. By controllably initializing the nuclear spins to $$\left\vert \Downarrow \Downarrow \Downarrow \right\rangle$$ ⇓ ⇓ ⇓ , we achieve single-electron qubit gate fidelities of F = 99.78 ± 0.07% (Clifford gate fidelities of 99.58 ± 0.14%), above the fault-tolerant threshold for the surface code with a coherence time of $${T}_{2}^{\,* }=12\,\upmu {{{\rm{s}}}}$$ T 2 * = 12 μ s .

Nature NanotechnologyFeb 7, 202424 citations

Electron Spin Qubit in Semiconductor—1-Qubit and 2-Qubit Gates

Hiu Yung Wong

Springer eBooksJan 1, 20250 citations

The remarkable prospect for quantum-dot-coupled tin qubits in silicon

Wayne M. Witzel, Jesse J. Lutz, Dwight Luhman

arXiv:2206.06285Jun 13, 20220 citations

High-fidelity readout and control of a nuclear spin qubit in silicon

Jarryd J. Pla, Kuan Yen Tan, Juan Pablo Dehollain +6 more

arXiv:1302.0047NatureApr 1, 2013533 citations

Tin as a nuclear spin qubit in silicon

Wayne M. Witzel

Published Mar 1, 2024• 0 citations

Publisher

Abstract

for single-qubit Clifford gates Micromagnet Array of 6 Loss-DiVincenzo qubits Combining nuclear and electron qubits 5

DOI: 10.2172/2540383

Related papers

Tin as a nuclear spin qubit in silicon.

Wayne M. Witzel, Dwight Luhman, Jesse J. Lutz +7 more

Aug 1, 20220 citations

Micromagnet-free operation of electron spin qubits in Si/Si $_{1-x}$ Ge $_x$ vertical double quantum dotsMicromagnet-free operation of electron spin qubits in Si/Si$_{1-x}$Ge$_x$ vertical double quantum dots

Abhikbrata Sarkar, Daniel Loss

We study a vertical double quantum dot (DQD) in a Si/Si $_{1-x}$ Ge $_x$ /Si double-well heterostructure for full electrical control of electron Loss-DiVincenzo (LD) spin qubits, using realistic device modeling and numerical simulations. Due to the emerging spin-orbit interaction in the DQD, as well as strain from the gate electrodes, small (percentage range) but finite $g$ tensor variations emerge. In addition, we find a large valley splitting, on the order of $E_v{\sim}250\,μ$ eV. As a result, multiple avenues for fast electrical single qubit rotations emerge. An ac electric field gives rise to electric dipole spin resonance (EDSR), while electron spin resonance (ESR) in the presence of an ac magnetic field can be electrically controlled by local gates due to varying $g$ factors in DQDs. We also show that shuttling between neighboring dots, in vertical and horizontal direction, results in ultrafast single qubit gates of less than a nanosecond. Remarkably, this DQD architecture completely eliminates the need for micromagnets, significantly facilitating the scalability of LD spin qubits in semiconductor foundries.We study a vertical double quantum dot (DQD) in a Si/Si$_{1-x}$Ge$_x$/Si double-well heterostructure for full electrical control of electron Loss-DiVincenzo (LD) spin qubits, using realistic device modeling and numerical simulations. Due to the emerging spin-orbit interaction in the DQD, as well as strain from the gate electrodes, small (percentage range) but finite $g$ tensor variations emerge. In addition, we find a large valley splitting, on the order of $E_v{\sim}250\,μ$eV. As a result, multiple avenues for fast electrical single qubit rotations emerge. An ac electric field gives rise to electric dipole spin resonance (EDSR), while electron spin resonance (ESR) in the presence of an ac magnetic field can be electrically controlled by local gates due to varying $g$ factors in DQDs. We also show that shuttling between neighboring dots, in vertical and horizontal direction, results in ultrafast single qubit gates of less than a nanosecond. Remarkably, this DQD architecture completely eliminates the need for micromagnets, significantly facilitating the scalability of LD spin qubits in semiconductor foundries.

cond-mat.mes-hallCross-listedarXiv:2512.19785Dec 24, 2025

High-fidelity initialization and control of electron and nuclear spins in a four-qubit register

Jan-Michael Reiner, Yousun Chung, S. H. Misha +15 more

Abstract Single electron spins bound to multi-phosphorus nuclear spin registers in silicon have demonstrated fast (0.8 ns) two-qubit $\sqrt{\mathrm{SWAP}}$ SWAP gates and long spin relaxation times (~30 s). In these spin registers, when the donors are ionized, the nuclear spins remain weakly coupled to their environment, allowing exceptionally long coherence times. When the electron is present, the hyperfine interaction allows coupling of the spin and charge degrees of freedom for fast qubit operation and control. Here we demonstrate the use of the hyperfine interaction to enact electric dipole spin resonance to realize high-fidelity ( $F=10{0}_{-6}^{+0}$ F = 10 0 − 6 + 0 %) initialization of all the nuclear spins within a four-qubit nuclear spin register. By controllably initializing the nuclear spins to $\left\vert \Downarrow \Downarrow \Downarrow \right\rangle$ ⇓ ⇓ ⇓ , we achieve single-electron qubit gate fidelities of F = 99.78 ± 0.07% (Clifford gate fidelities of 99.58 ± 0.14%), above the fault-tolerant threshold for the surface code with a coherence time of $${T}_{2}^{\,* }=12\,\upmu {{{\rm{s}}}}$$ T 2 * = 12 μ s .Abstract Single electron spins bound to multi-phosphorus nuclear spin registers in silicon have demonstrated fast (0.8 ns) two-qubit $$\sqrt{\mathrm{SWAP}}$$ SWAP gates and long spin relaxation times (~30 s). In these spin registers, when the donors are ionized, the nuclear spins remain weakly coupled to their environment, allowing exceptionally long coherence times. When the electron is present, the hyperfine interaction allows coupling of the spin and charge degrees of freedom for fast qubit operation and control. Here we demonstrate the use of the hyperfine interaction to enact electric dipole spin resonance to realize high-fidelity ( $$F=10{0}_{-6}^{+0}$$ F = 10 0 − 6 + 0 %) initialization of all the nuclear spins within a four-qubit nuclear spin register. By controllably initializing the nuclear spins to $$\left\vert \Downarrow \Downarrow \Downarrow \right\rangle$$ ⇓ ⇓ ⇓ , we achieve single-electron qubit gate fidelities of F = 99.78 ± 0.07% (Clifford gate fidelities of 99.58 ± 0.14%), above the fault-tolerant threshold for the surface code with a coherence time of $${T}_{2}^{\,* }=12\,\upmu {{{\rm{s}}}}$$ T 2 * = 12 μ s .

Nature NanotechnologyFeb 7, 202424 citations

Electron Spin Qubit in Semiconductor—1-Qubit and 2-Qubit Gates

Hiu Yung Wong

Springer eBooksJan 1, 20250 citations

The remarkable prospect for quantum-dot-coupled tin qubits in silicon

Wayne M. Witzel, Jesse J. Lutz, Dwight Luhman

Spin- $\frac{1}{2}$ $^{119}$ Sn nuclei in a silicon semiconductor could make excellent qubits. Nuclear spins in silicon are known to have long coherence times. Tin is isoelectronic with silicon, so we expect electrons can easily shuttle from one Sn atom to another to propagate quantum information via a hyperfine interaction that we predict, from all-electron linearized augmented plane wave density functional theory calculations, to be roughly ten times larger than intrinsic $^{29}$ Si. A hyperfine-induced electro-nuclear controlled-phase (e-n-CPhase) gate operation, generated (up to local rotations) by merely holding an electron at a sweet-spot of maximum hyperfine strength for a specific duration of time, is predicted to be exceptionally resilient to charge/voltage noise. Diabatic spin flips are suppressed with a modest magnetic field ( $>15~$ mT for $<10^{-6}$ flip probabilities) and nuclear spin bath noise may be avoided via isotopic enrichment or mitigated using dynamical decoupling or through monitoring and compensation. Combined with magnetic resonance control, this operation enables universal quantum computation.Spin-$\frac{1}{2}$ $^{119}$Sn nuclei in a silicon semiconductor could make excellent qubits. Nuclear spins in silicon are known to have long coherence times. Tin is isoelectronic with silicon, so we expect electrons can easily shuttle from one Sn atom to another to propagate quantum information via a hyperfine interaction that we predict, from all-electron linearized augmented plane wave density functional theory calculations, to be roughly ten times larger than intrinsic $^{29}$Si. A hyperfine-induced electro-nuclear controlled-phase (e-n-CPhase) gate operation, generated (up to local rotations) by merely holding an electron at a sweet-spot of maximum hyperfine strength for a specific duration of time, is predicted to be exceptionally resilient to charge/voltage noise. Diabatic spin flips are suppressed with a modest magnetic field ($>15~$mT for $<10^{-6}$ flip probabilities) and nuclear spin bath noise may be avoided via isotopic enrichment or mitigated using dynamical decoupling or through monitoring and compensation. Combined with magnetic resonance control, this operation enables universal quantum computation.

arXiv:2206.06285Jun 13, 20220 citations

High-fidelity readout and control of a nuclear spin qubit in silicon

Jarryd J. Pla, Kuan Yen Tan, Juan Pablo Dehollain +6 more

arXiv:1302.0047NatureApr 1, 2013533 citations

Micromagnet-free operation of electron spin qubits in Si/Si

_{1-x}

_x

vertical double quantum dots

We study a vertical double quantum dot (DQD) in a Si/Si

_{1-x}

_x

/Si double-well heterostructure for full electrical control of electron Loss-DiVincenzo (LD) spin qubits, using realistic device modeling and numerical simulations. Due to the emerging spin-orbit interaction in the DQD, as well as strain from the gate electrodes, small (percentage range) but finite

g

tensor variations emerge. In addition, we find a large valley splitting, on the order of

E_v{\sim}250\,μ

eV. As a result, multiple avenues for fast electrical single qubit rotations emerge. An ac electric field gives rise to electric dipole spin resonance (EDSR), while electron spin resonance (ESR) in the presence of an ac magnetic field can be electrically controlled by local gates due to varying

g

factors in DQDs. We also show that shuttling between neighboring dots, in vertical and horizontal direction, results in ultrafast single qubit gates of less than a nanosecond. Remarkably, this DQD architecture completely eliminates the need for micromagnets, significantly facilitating the scalability of LD spin qubits in semiconductor foundries.

Abstract Single electron spins bound to multi-phosphorus nuclear spin registers in silicon have demonstrated fast (0.8 ns) two-qubit

\sqrt{\mathrm{SWAP}}

SWAP gates and long spin relaxation times (~30 s). In these spin registers, when the donors are ionized, the nuclear spins remain weakly coupled to their environment, allowing exceptionally long coherence times. When the electron is present, the hyperfine interaction allows coupling of the spin and charge degrees of freedom for fast qubit operation and control. Here we demonstrate the use of the hyperfine interaction to enact electric dipole spin resonance to realize high-fidelity (

F=10{0}_{-6}^{+0}

F = 10 0 − 6 + 0 %) initialization of all the nuclear spins within a four-qubit nuclear spin register. By controllably initializing the nuclear spins to

\left\vert \Downarrow \Downarrow \Downarrow \right\rangle

⇓ ⇓ ⇓ , we achieve single-electron qubit gate fidelities of F = 99.78 ± 0.07% (Clifford gate fidelities of 99.58 ± 0.14%), above the fault-tolerant threshold for the surface code with a coherence time of $${T}_{2}^{\,* }=12\,\upmu {{{\rm{s}}}}$$ T 2 * = 12 μ s .

Spin-

\frac{1}{2}

^{119}

Sn nuclei in a silicon semiconductor could make excellent qubits. Nuclear spins in silicon are known to have long coherence times. Tin is isoelectronic with silicon, so we expect electrons can easily shuttle from one Sn atom to another to propagate quantum information via a hyperfine interaction that we predict, from all-electron linearized augmented plane wave density functional theory calculations, to be roughly ten times larger than intrinsic

^{29}

Si. A hyperfine-induced electro-nuclear controlled-phase (e-n-CPhase) gate operation, generated (up to local rotations) by merely holding an electron at a sweet-spot of maximum hyperfine strength for a specific duration of time, is predicted to be exceptionally resilient to charge/voltage noise. Diabatic spin flips are suppressed with a modest magnetic field (

>15~

mT for

<10^{-6}

flip probabilities) and nuclear spin bath noise may be avoided via isotopic enrichment or mitigated using dynamical decoupling or through monitoring and compensation. Combined with magnetic resonance control, this operation enables universal quantum computation.