Electrically controlled quantum gates for two-spin qubits in two double quantum dots

Abstract

Exchange-coupled singlet-triplet spin qubits in two gate-defined double quantum dots are considered theoretically. Using charge density operators to describe the double-dot orbital states, we calculate the Coulomb couplings between the qubits, and identify optimal bias points for single- and two-qubit operations, as well as convenient idle positions. The same intuitive formulation is used to derive dephasing rates of these qubits due to the fluctuating charge environment, thereby providing the main considerations for a quantum computation architecture that is within current experimental capabilities.

9 pages, 7 figures

References in corpus (8)

• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Enhancing the Coherence of a Spin Qubit by Operating it as a Feedback Loop That Controls its Nuclear Spin Bath
• Pure quantum dephasing of a solid state electron spin qubit in a large nuclear spin bath coupled by long-range hyperfine-mediated interactions
• Decoherence in qubits due to low-frequency noise
• Universal set of quantum gates for double-dot spin qubits with fixed interdot coupling
• Conditional operation of a spin qubit
• Quantum gates between capacitively coupled double quantum dot two-spin qubits
• Semi-classical model for the dephasing of a two-electron spin qubit coupled to a coherently evolving nuclear spin bath

Cited by in corpus (23)

• Composite pulses for robust universal control of singlet-triplet qubits
• Robust quantum gates for singlet-triplet spin qubits using composite pulses
• Three-electron spin qubits
• Robust two-qubit gates for donors in silicon controlled by hyperfine interactions
• Randomized benchmarking of barrier versus tilt control of a singlet-triplet qubit
• Controllable exchange coupling between two singlet-triplet qubits
• Hybrid spin and valley quantum computing with singlet-triplet qubits
• Neural-network-designed pulse sequences for robust control of singlet-triplet qubits
• Directly accessible entangling gates for capacitively coupled singlet-triplet qubits
• Capacitively coupled singlet-triplet qubits in the double charge resonant regime
• Fast pulse sequences for dynamically corrected gates in single-triplet qubits
• Coherent electrical rotations of valley states in Si quantum dots using the phase of the valley-orbit coupling
• Dynamical decoupling of a singlet-triplet qubit afflicted by a charge fluctuator
• Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field
• Capacitative coupling of singlet-triplet qubits in different inter-qubit geometries
• Maximal tripartite entanglement between singlet-triplet qubits in quantum dots
• Nonmonotonic buildup of spin-singlet correlations in a double quantum dot
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• Energy spectrum, exchange interaction and gate crosstalk in a pair of double-quantum-dot system: a molecular orbital calculation
• A robust operating point for capacitively coupled singlet-triplet qubits
• Rapid adiabatic gating for capacitively coupled quantum dot hybrid qubits without barrier control
• Minimal Non-orthogonal Gate Decomposition for Qubits with Limited Control
• Enhanced local addressability of a spin array with local exchange pulses and global microwave driving