The SpinBus Architecture: Scaling Spin Qubits with Electron Shuttling (2306.16348v1)
Abstract: Quantum processor architectures must enable scaling to large qubit numbers while providing two-dimensional qubit connectivity and exquisite operation fidelities. For microwave-controlled semiconductor spin qubits, dense arrays have made considerable progress, but are still limited in size by wiring fan-out and exhibit significant crosstalk between qubits. To overcome these limitations, we introduce the SpinBus architecture, which uses electron shuttling to connect qubits and features low operating frequencies and enhanced qubit coherence. Device simulations for all relevant operations in the Si/SiGe platform validate the feasibility with established semiconductor patterning technology and operation fidelities exceeding 99.9 %. Control using room temperature instruments can plausibly support at least 144 qubits, but much larger numbers are conceivable with cryogenic control circuits. Building on the theoretical feasibility of high-fidelity spin-coherent electron shuttling as key enabling factor, the SpinBus architecture may be the basis for a spin-based quantum processor that meets the scalability requirements for practical quantum computing.
- Roads towards fault-tolerant universal quantum computation. Nature 549, 172–179 (2017).
- Zwerver, A. M. J. et al. Qubits made by advanced semiconductor manufacturing. Nat. Electron. 5, 184–190 (2022).
- Yoneda, J. et al. A quantum-dot spin qubit with coherence limited by charge noise and fidelity higher than 99.9%. Nat. Nanotechnol. 13, 102–106 (2018).
- Zajac, D. M. et al. Resonantly driven CNOT gate for electron spins. Science 359, 439–442 (2018).
- Watson, T. F. et al. A programmable two-qubit quantum processor in silicon. Nature 555, 633–637 (2018).
- Xue, X. et al. Benchmarking gate fidelities in a Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe two-qubit device. Phys. Rev. X 9, 021011 (2019).
- Petit, L. et al. Universal quantum logic in hot silicon qubits. Nature 580, 355–359 (2020).
- Xue, X. et al. Quantum logic with spin qubits crossing the surface code threshold. Nature 601, 343–347 (2022).
- Noiri, A. et al. Fast universal quantum gate above the fault-tolerance threshold in silicon. Nature 601, 338–342 (2022).
- Quantum error correction with silicon spin qubits. Nature 608, 682–686 (2022).
- Mills, A. R. et al. Two-qubit silicon quantum processor with operation fidelity exceeding 99%. Sci. Adv. 8, eabn5130 (2022).
- Lawrie, W. I. L. et al. Quantum dot arrays in silicon and germanium. Appl. Phys. Lett. 116, 080501 (2020).
- Mortemousque, P.-A. et al. Coherent control of individual electron spins in a two-dimensional array of quantum dots. Nat. Nanotechnol. 16, 296–301 (2021).
- Weinstein, A. J. et al. Universal logic with encoded spin qubits in silicon. Nature 615, 817–822 (2023).
- Philips, S. G. J. et al. Universal control of a six-qubit quantum processor in silicon. Nature 609, 919–924 (2022).
- Undseth, B. et al. Nonlinear response and crosstalk of electrically driven silicon spin qubits. Phys. Rev. Appl. 19, 044078 (2023).
- Vandersypen, L. et al. Interfacing spin qubits in quantum dots and donors—hot, dense, and coherent. npj Quantum Inf. 3, 34 (2017).
- Li, R. et al. A crossbar network for silicon quantum dot qubits. Sci. Adv. 4, eaar3960 (2018).
- Silicon cmos architecture for a spin-based quantum computer. Nat. Commun. 8, 1766 (2017).
- Control electronics for semiconductor spin qubits. Quantum Sci. Technol. 5, 015004 (2020).
- Boter, J. M. et al. Spiderweb array: A sparse spin-qubit array. Phys. Rev. Appl. 18, 024053 (2022).
- Baart, T. A. et al. Single-spin CCD. Nat. Nanotechnol. 11, 330–334 (2016).
- Flentje, H. et al. Coherent long-distance displacement of individual electron spins. Nat. Commun. 8, 501 (2017).
- Mills, A. et al. Shuttling a single charge across a one-dimensional array of silicon quantum dots. Nat Commun. 10, 1063 (2019).
- Yoneda, J. et al. Coherent spin qubit transport in silicon. Nat. Commun. 12, 4114 (2021).
- Noiri, A. et al. A shuttling-based two-qubit logic gate for linking distant silicon quantum processors. Nat. Commun. 13, 5740 (2022).
- Zwerver, A. et al. Shuttling an electron spin through a silicon quantum dot array. Preprint at https://arxiv.org/abs/2209.00920 (2022).
- Seidler, I. et al. Conveyor-mode single-electron shuttling in Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe for a scalable quantum computing architecture. npj Quantum Inf. 8, 100 (2022).
- Xue, R. et al. Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe QuBus with memory and connectivity function for single carrier information processing devices over micron scale distances. In preparation (2023).
- Langrock, V. et al. Blueprint of a scalable spin qubit shuttle device for coherent mid-range qubit transfer in disordered Si/SiGe/SiO2SiSiGesubscriptSiO2\mathrm{Si}/\mathrm{SiGe}/\mathrm{SiO_{2}}roman_Si / roman_SiGe / roman_SiO start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT. PRX Quantum 4, 020305 (2023).
- Struck, T. et al. Spin-EPREPR\mathrm{EPR}roman_EPR-pair separation by conveyor-mode single electron shuttling in Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe. In preparation (2023).
- Current rectification by pauli exclusion in a weakly coupled double quantum dot system. Science 297, 1313–1317 (2002).
- Rapid high-fidelity spin-state readout in SiSi\mathrm{Si}roman_Si/SiSi\mathrm{Si}roman_Si-GeGe\mathrm{Ge}roman_Ge quantum dots via rf reflectometry. Phys. Rev. Appl. 13, 024019 (2020).
- Cryogenic amplifier for fast real-time detection of single-electron tunneling. Appl. Phys. Lett. 91, 123512 (2007).
- Tracy, L. A. et al. Single shot spin readout using a cryogenic high-electron-mobility transistor amplifier at sub-Kelvin temperatures. Appl. Phys. Lett. 108, 063101 (2016).
- Curry, M. J. et al. Single-Shot Readout Performance of Two Heterojunction-Bipolar-Transistor Amplification Circuits at Millikelvin Temperatures. Sci. Rep. 9, 16976 (2019).
- Quantum computation with quantum dots. Phys. Rev. A 57, 120–126 (1998).
- Efficient controlled-phase gate for single-spin qubits in quantum dots. Phys. Rev. B 83, 121403 (2011).
- Russ, M. et al. High-fidelity quantum gates in Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe double quantum dots. Phys. Rev. B 97, 085421 (2018).
- Petit, L. et al. Design and integration of single-qubit rotations and two-qubit gates in silicon above one Kelvin. Commun. Mater. 3, 82 (2022).
- qopt: An experiment-oriented software package for qubit simulation and quantum optimal control. Phys. Rev. Applied 17, 034036 (2022).
- Dial, O. E. et al. Charge noise spectroscopy using coherent exchange oscillations in a singlet-triplet qubit. Phys. Rev. Lett. 110 (2013).
- Kranz, L. et al. Exploiting a single-crystal environment to minimize the charge noise on qubits in silicon. Adv. Mater. 32, 2003361 (2020).
- Cerfontaine, P. et al. Closed-loop control of a GaAsGaAs\mathrm{GaAs}roman_GaAs-based singlet-triplet spin qubit with 99.5 % gate fidelity and low leakage. Nat. Commun. 11, 4144 (2022).
- Surface codes: Towards practical large-scale quantum computation. Phys. Rev. A 86, 032324 (2012).
- Bluefors XLDsl Dilution Refrigerator System. https://bluefors.com/products/xldsl-dilution-refrigerator (Accessed: 2023-06-27).
- Donahue, M. Oommf user’s guide, version 1.0 (1999).
- Simulation of micro-magnet stray-field dynamics for spin qubit manipulation. J. Appl. Phys. 117, 193903 (2015).
- Valley splitting theory of SiGe/Si/SiGeSiGeSiSiGe\mathrm{Si}\mathrm{Ge}/\mathrm{Si}/\mathrm{Si}\mathrm{Ge}roman_SiGe / roman_Si / roman_SiGe quantum wells. Phys. Rev. B 75, 115318 (2007).
- Quantification and characterization of leakage errors. Phys. Rev. A 97 (2018).
- Wuetz, B. P. et al. Atomic fluctuations lifting the energy degeneracy in Si/SiGeSiSiGe\mathrm{Si}/\mathrm{Si}\mathrm{Ge}roman_Si / roman_SiGe quantum dots. Nat. Commun. 13, 7730 (2022).
- Hollmann, A. et al. Large, tunable valley splitting and single-spin relaxation mechanisms in a SiSi\mathrm{Si}roman_Si/SixsubscriptSi𝑥\mathrm{Si}_{x}roman_Si start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPTGe1−xsubscriptGe1𝑥\mathrm{Ge}_{1-x}roman_Ge start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPT quantum dot. Phys. Rev. Appl. 13, 034068 (2020).
- Watts, P. et al. Optimizing for an arbitrary perfect entangler. I. Functionals. Phys. Rev. A 91 (2015).
- Vandersypen, L. M. K. et al. Experimental realization of Shor’s quantum factoring algorithm using nuclear magnetic resonance. Nature 414, 883–887 (2001).
- McJunkin, T. et al. Valley splittings in Si/SiGeSiSiGe\mathrm{Si}/\mathrm{SiGe}roman_Si / roman_SiGe quantum dots with a germanium spike in the silicon well. Phys. Rev. B 104, 085406 (2021).
- McJunkin, T. et al. SiGeSiGe\mathrm{SiGe}roman_SiGe quantum wells with oscillating GeGe\mathrm{Ge}roman_Ge concentrations for quantum dot qubits. Nat. Commun. 13, 1–7 (2022).
- AMD EPYC™ 9654. https://www.amd.com/en/products/cpu/amd-epyc-9654 (Accessed: 2023-06-27).
- Ardent Concepts High Density TR Multicoax™ Cabling. https://www.ardentconcepts.com/quantum-overview (Accessed: 2023-06-27).
- Rosenberger WSMP® NEW GENERATION connectors. https://www.rosenberger.com/product/wsmp/ (Accessed: 2023-06-27).
- High-Density Cryogenic Wiring for Superconducting Qubit Control. Patent US20220230785A1 (2022).
- Otten, R. et al. Qubit Bias using a CMOS DAC at mK Temperatures. In 2022 29th IEEE International Conference on Electronics, Circuits and Systems (ICECS) (2022).
- Zoschke, K. et al. High Density Flex and Thin Chip Embedding Technology for Polymeric Interposer and Sensor Packaging Applications. In 2019 International Wafer Level Packaging Conference (IWLPC), 1–9 (2019).
- Bluhm, H. Isolator für kryoelektrische Chips bei extrem niedrigen Temperaturen unter 10K. Patent DE102021123046 (2021).
- Pauka, S. J. et al. A cryogenic CMOS chip for generating control signals for multiple qubits. Nat. Electron. 4, 64–70 (2021).
- Bohuslavskyi, H. et al. Scalable on-chip multiplexing of low-noise silicon electron and hole quantum dots. Preprint at https://arxiv.org/abs/2208.12131 (2022).
- Kammerloher, E. et al. Sensing dot with high output swing for scalable baseband readout of spin qubits. Preprint at https://arxiv.org/abs/2107.13598 (2023).
- Seidler, I. et al. Tailoring potentials by simulation-aided design of gate layouts for spin qubit applications. Preprint at https://arxiv.org/abs/2303.13358 (2023).