Efficient Two-Qubit Pulse Sequences Beyond CNOT

Abstract

We design efficient controlled-rotation gates with arbitrary angle acting on three-spin encoded qubits for exchange-only quantum computation. Two pulse sequence constructions are given. The first is motivated by an analytic derivation of the efficient Fong-Wandzura sequence for an exact CNOT gate. This derivation, briefly reviewed here, is based on elevating short sequences of SWAP pulses to an entangling two-qubit gate. To go beyond CNOT, we apply a similar elevation to a modified short sequence consisting of SWAPs and one pulse of arbitrary duration. This results in two-qubit sequences that carry out controlled-rotation gates of arbitrary angle. The second construction streamlines a class of arbitrary CPHASE gates established earlier. Both constructions are based on building two-qubit sequences out of subsequences with special properties that render each step of the construction analytically tractable.

arXiv comment20 pages, 13 figures, published version

References in corpus (34)

• Quantum Computing in the NISQ era and beyond
• Quantum Computation with Quantum Dots
• A variational eigenvalue solver on a quantum processor
• The theory of variational hybrid quantum-classical algorithms
• Universal Quantum Computation with the Exchange Interaction
• Experimental ten-photon entanglement
• Theory of Decoherence-Free Fault-Tolerant Universal Quantum Computation
• Theory of variational quantum simulation
• Universal quantum computation with spin-1/2 pairs and Heisenberg exchange
• Universal Fault-Tolerant Computation on Decoherence-Free Subspaces
• Reduced sensitivity to charge noise in semiconductor spin qubits via symmetric operation
• Quantum control and process tomography of a semiconductor quantum dot hybrid qubit
• Coherent control of three-spin states in a triple quantum dot
• Coherent spin manipulation in an exchange-only qubit
• Self-Consistent Measurement and State Tomography of an Exchange-Only Spin Qubit
• The Resonant Exchange Qubit
• A fast "hybrid" silicon double quantum dot qubit
• Electrically-protected resonant exchange qubits in triple quantum dots
• Three-electron spin qubits
• Extending the coherence of a quantum dot hybrid qubit
• Tunable Hybrid Qubit in a GaAs Double Quantum Dot
• Pulse-gated quantum dot hybrid qubit
• Quantifying error and leakage in an encoded Si/SiGe triple-dot qubit
• Charge-noise-insensitive gate operations for always-on, exchange-only qubits
• Two-Qubit Gates for Resonant Exchange Qubits
• Energetic Suppression of Decoherence in Exchange-Only Quantum Computation
• Robust Two-Qubit Gates for Exchange-Coupled Qubits
• Universal Set of Quantum Gates for Double-Dot Exchange-Only Spin Qubits with Intradot Coupling
• A tunable hybrid qubit in a triple quantum dot
• Analytic Pulse Sequence Construction for Exchange-Only Quantum Computation
• A Simple Derivation of the Fong-Wandzura Pulse Sequence
• Characterisation of an exchange-based two-qubit gate for resonant exchange qubits
• Approximate exchange-only entangling gates for the three-spin-$1/2$ decoherence-free subsystem
• Gauge-invariant Adiabatic Two-Qubit Gates for Exchange-Only Qubits

Cited by in corpus (3)

• Semiconductor Spin Qubits
• Segmented Composite Design of Robust Single-Qubit Quantum Gates
• Jenga-Krotov algorithm: Efficient compilation of multi-qubit gates for exchange-only qubits