A Spin Quintet in a Silicon Double Quantum Dot: Spin Blockade and Relaxation

Abstract

Spins in gate-defined silicon quantum dots are promising candidates for implementing large-scale quantum computing. To read the spin state of these qubits, the mechanism that has provided the highest fidelity is spin-to-charge conversion via singlet-triplet spin blockade, which can be detected in-situ using gate-based dispersive sensing. In systems with a complex energy spectrum, like silicon quantum dots, accurately identifying when singlet-triplet blockade occurs is hence of major importance for scalable qubit readout. In this work, we present a description of spin blockade physics in a tunnel-coupled silicon double quantum dot defined in the corners of a split-gate transistor. Using gate-based magnetospectroscopy, we report successive steps of spin blockade and spin blockade lifting involving spin states with total spin angular momentum up to $S=3$. More particularly, we report the formation of a hybridized spin quintet state and show triplet-quintet and quintet-septet spin blockade. This enables studies of the quintet relaxation dynamics from which we find $T_1\sim 4\mu s$. Finally, we develop a quantum capacitance model that can be applied generally to reconstruct the energy spectrum of a double quantum dot including the spin-dependent tunnel couplings and the energy splitting between different spin manifolds. Our results open for the possibility of using Si CMOS quantum dots as a tuneable platform for studying high-spin systems.

arXiv comment7 pages, 3 figures

References in corpus (41)

• Electron transport through double quantum dots
• A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
• Single-shot readout of an electron spin in silicon
• A programmable two-qubit quantum processor in silicon
• Electron spin coherence exceeding seconds in high purity silicon
• A CMOS silicon spin qubit
• Prospects for Spin-Based Quantum Computing
• Room temperature quantum bit storage exceeding 39 minutes using ionized donors in 28-silicon
• Silicon CMOS architecture for a spin-based quantum computer
• Silicon quantum processor unit cell operation above one Kelvin
• Fidelity benchmarks for two-qubit gates in silicon
• A fast "hybrid" silicon double quantum dot qubit
• Dispersive Readout of a Few-Electron Double Quantum Dot with Fast rf Gate-Sensors
• A high-sensitivity gate-based charge sensor in silicon
• Gate-based single-shot readout of spins in silicon
• Beyond Triplet: Unconventional Superconductivity in a Spin-3/2 Topological Semimetal
• Charge and spin state readout of a double quantum dot coupled to a resonator
• Gate-reflectometry dispersive readout and coherent control of a spin qubit in silicon
• Pauli Spin Blockade in a Highly Tunable Silicon Double Quantum Dot
• Electrically driven electron spin resonance mediated by spin-valley-orbit coupling in a silicon quantum dot
• Valley-based noise-resistant quantum computation using Si quantum dots
• Integrated silicon qubit platform with single-spin addressability, exchange control and robust single-shot singlet-triplet readout
• Single-shot measurement of triplet-singlet relaxation in a Si/SiGe double quantum dot
• Electrical control of g-factors in a few-hole silicon nanowire MOSFET
• Quantum and Tunnelling Capacitance in Charge and Spin Qubits
• Dispersively detected Pauli Spin-Blockade in a Silicon Nanowire Field-Effect Transistor
• Coherent spin control of s-, p-, d- and f-electrons in a silicon quantum dot
• Radio-frequency capacitive gate-based sensing
• High-fidelity single-shot readout for a spin qubit via an enhanced latching mechanism
• Single-spin qubits in isotopically enriched silicon at low magnetic field
• A Radio Frequency Charge Parity Meter
• Single-shot single-gate RF spin readout in silicon
• Coherence and Screening in Multi-Electron Spin Qubits
• All-electrical manipulation of silicon spin qubits with tunable spin-valley mixing
• Spin-orbit dynamics of single acceptor atoms in silicon
• Singlet-Quintet Mixing in Spin-Orbit Coupled Superconductors with j=3/2 Fermions
• Spin of a multielectron quantum dot and its interaction with a neighboring electron
• Six-electron semiconductor double quantum dot qubits
• Electric-field tuning of the valley splitting in silicon corner dots
• Spin blockade and coherent dynamics of high-spin states in a three-electron double quantum dot
• Microwave cavity detected spin blockade in a few electron double quantum dot

Cited by in corpus (12)

• Probing quantum devices with radio-frequency reflectometry
• Hole spin qubits in Si FinFETs with fully tunable spin-orbit coupling and sweet spots for charge noise
• Large dispersive interaction between a CMOS double quantum dot and microwave photons
• Two-body Wigner molecularization in asymmetric quantum dot spin qubits
• Hole spin qubits in thin curved quantum wells
• Controlling Synthetic Spin-Orbit Coupling in a Silicon Quantum Dot with Magnetic Field
• Voltage-controlled Hubbard spin transistor
• Gate reflectometry in dense quantum dot arrays
• Dynamical charge susceptibility in nonequilibrium double quantum dots
• Proposal for a cavity-induced measurement of the exchange coupling in quantum dots
• Electrical readout of spins in the absence of spin blockade
• Interplay of Pauli blockade with electron-photon coupling in quantum dots