Resonantly Driven Singlet-Triplet Spin Qubit in Silicon.

@article{Takeda2019ResonantlyDS,
  title={Resonantly Driven Singlet-Triplet Spin Qubit in Silicon.},
  author={Kenta Takeda and Akito Noiri and Jun Yoneda and Takashi Nakajima and Seigo Tarucha},
  journal={Physical review letters},
  year={2019},
  volume={124 11},
  pages={
          117701
        }
}
We report implementation of a resonantly driven singlet-triplet spin qubit in silicon. The qubit is defined by the two-electron antiparallel spin states and universal quantum control is provided through a resonant drive of the exchange interaction at the qubit frequency. The qubit exhibits long T_{2}^{*} exceeding 1  μs that is limited by dephasing due to the ^{29}Si nuclei rather than charge noise thanks to the symmetric operation and a large micromagnet Zeeman field gradient. The randomized… 

Figures from this paper

Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field

Charge noise is the main hurdle preventing high-fidelity operation, in particular that of two-qubit gates, of semiconductor-quantum-dot-based spin qubits. While certain sweet spots where charge noise

A singlet-triplet hole spin qubit in planar Ge

A hole spin qubit is demonstrated operating at fields below 10 mT, the critical field of Al, by exploiting the large out-of-plane hole g-factors in planar Ge and by encoding the qubit into the singlet-triplet states of a double quantum dot.

Closed-loop control of a GaAs-based singlet-triplet spin qubit with 99.5% gate fidelity and low leakage

Pulse optimization and closed-loop control are used to achieve a gate fidelity of 99.5% for exchange-based single-qubit gates of two-electron spin qubits in GaAs, which opens new perspectives for microwave-free control of singlet-triplet qubitsIn GaAs and other materials.

Coherent spin qubit transport in silicon

High-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon is demonstrated, reinforcing the scaling prospects of silicon-based spin qubits.

Perspective on exchange-coupled quantum-dot spin chains

Electron spins in semiconductor quantum dots are a promising platform for quantum-information processing applications because their quantum phase coherence can persist for extremely long times.

Adiabatic quantum state transfer in a semiconductor quantum-dot spin chain

Evidence of adiabatic quantum-state transfer in a chain of semiconductor quantum-dot electron spins is presented, and this method will be useful for initialization, state distribution, and readout in large spin-qubit arrays for gate-based quantum computing.

Protecting quantum information in quantum dot spin chains by driving exchange interactions periodically

Recent work has demonstrated a new route to discrete time crystal physics in quantum spin chains by periodically driving nearest-neighbor exchange interactions in gate-defined quantum dot arrays

A shuttling-based two-qubit logic gate for linking distant silicon quantum processors

Control of entanglement between qubits at distant quantum processors using a two-qubit gate is an essential function of a scalable, modular implementation of quantum computation. Among the many qubit

Approaching Ideal Visibility in Singlet-Triplet Qubit Operations Using Energy-Selective Tunneling-Based Hamiltonian Estimation.

We report energy-selective tunneling readout-based Hamiltonian parameter estimation of a two-electron spin qubit in a GaAs quantum dot array. Optimization of readout fidelity enables a single-shot

Quantum Dots / Spin Qubits

Summary: Spin qubits in semiconductor quantum dots represent a prominent family of solid-state qubits in the effort to build a quantum computer. They are formed when electrons or holes are confined in

References

SHOWING 1-10 OF 39 REFERENCES

Site-Selective Quantum Control in an Isotopically Enriched Si28/Si0.7Ge0.3 Quadruple Quantum Dot

Silicon spin qubits are a promising quantum computing platform offering long coherence times, small device sizes, and compatibility with industry-backed device fabrication techniques. In recent

Quantum CNOT Gate for Spins in Silicon [1]

Single qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. While high fidelity single qubit operations have been achieved using the electron spin

Readout of singlet-triplet qubits at large magnetic field gradients

Visibility of singlet-triplet qubit readout is reduced to almost zero in large magnetic field gradients due to relaxation processes. Here we present a new readout technique that is robust against

Two-axis control of a singlet–triplet qubit with an integrated micromagnet

The fabrication and operation of a qubit in a double-quantum dot in a silicon/silicon–germanium (Si/SiGe) heterostructure in which the qubit states are singlet and triplet states of two electrons, a significant advance over previous work.

Noise Suppression Using Symmetric Exchange Gates in Spin Qubits.

We demonstrate a substantial improvement in the spin-exchange gate using symmetric control instead of conventional detuning in GaAs spin qubits, up to a factor of six increase in the quality factor

Coherent Manipulation of Coupled Electron Spins in Semiconductor Quantum Dots

We demonstrated coherent control of a quantum two-level system based on two-electron spin states in a double quantum dot, allowing state preparation, coherent manipulation, and projective readout.

A fast quantum interface between different spin qubit encodings

A hybrid device with two coupled semiconductor spin qubits of different designs, which should allow each qubit’s advantages to be exploited, will be useful to settle remaining key problems with building scalable spin-based quantum computers.

Reduced Sensitivity to Charge Noise in Semiconductor Spin Qubits via Symmetric Operation.

It is found that this method reduces the dephasing effect of charge noise by more than a factor of 5 in comparison to operation near a charge-state anticrossing, increasing the number of observable exchange oscillations in the authors' qubit by a similar factor.

Self-consistent measurement and state tomography of an exchange-only spin qubit.

Initiation, full control, and single-shot readout of a three-electron exchange-driven spin qubit is reported, allowing decoherence, leakage out of the qubit state space, and measurement fidelity to be quantified.

Isotopically enhanced triple-quantum-dot qubit

This work demonstrates universal coherent control of a triple-quantum-dot qubit implemented in an isotopically enhanced Si/SiGe heterostructure and demonstrates sufficient control with sufficiently low noise to enable the long pulse sequences required for exchange-only two-qubit logic and randomized benchmarking.