Hybrid spin and valley quantum computing with singlet-triplet qubits

Abstract

The valley degree of freedom in the electronic band structure of silicon, graphene, and other materials is often considered to be an obstacle for quantum computing (QC) based on electron spins in quantum dots. Here we show that control over the valley state opens new possibilities for quantum information processing. Combining qubits encoded in the singlet-triplet subspace of spin and valley states allows for universal QC using a universal two-qubit gate directly provided by the exchange interaction. We show how spin and valley qubits can be separated in order to allow for single-qubit rotations.

14 pages, 7 figures

References in corpus (21)

• The electronic properties of graphene
• Spin qubits in graphene quantum dots
• Coupling of Spin and Orbital Motion of Electrons in Carbon Nanotubes
• Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits
• Prospects for Spin-Based Quantum Computing
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Fidelity of quantum operations
• Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots
• Ultra-long distance interaction between spin qubits
• Physical mechanisms of interface-mediated intervalley coupling in Si
• Spin and valley-orbit splittings in SiGe/Si heterostructures
• Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
• Conditional operation of a spin qubit
• Quantum gates between capacitively coupled double quantum dot two-spin qubits
• Detection of a large valley-orbit splitting in silicon with two-donor spectroscopy
• Spin filling of valley-orbit states in a silicon quantum dot
• Orbital and valley state spectra of a few-electron silicon quantum dot
• Exchange-based two-qubit gate for singlet-triplet qubits
• Extended interface states enhance valley splitting in Si/SiO2
• Impact of the valley degree of freedom on the control of donor electrons near a Si/SiO_2 interface

Cited by in corpus (24)

• Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field
• Magnetic Proximity Effects in Transition-Metal Dichalcogenides: Converting Excitons
• Three-electron spin qubits
• Dynamical screening in monolayer transition-metal dichalcogenides and its manifestations in the exciton spectrum
• Valley dependent anisotropic spin splitting in silicon quantum dots
• Probing two-electron multiplets in bilayer graphene quantum dots
• Long distance coupling of resonant exchange qubits
• Spintronics with graphene quantum dots
• Switching between relaxation hotspots and coldspots in disordered spin qubits
• Signatures of atomic-scale structure in the energy dispersion and coherence of a Si quantum-dot qubit
• Performances and robustness of quantum teleportation with identical particles
• Mechanically induced two-qubit gates and maximally entangled states for single electron spins in a carbon nanotube
• Valley relaxation in graphene due to charged impurities
• Mass-profile quantum dots in graphene
• Direct measurement of electron intervalley relaxation in a Si/SiGe quantum dot
• Quantum state transfer between valley and photon qubits
• Anisotropy of spin coherence in high mobility quantum wells with arbitrary magnetic fields
• Theory of field-modulated spin-valley-orbital pseudospin physics
• Creating arbitrary quantum vibrational states in a carbon nanotube
• Vacancy-Induced Quantum Properties in 2D Silicon Carbide: Atomistic insights from semi-local and hybrid DFT calculations
• Assessment of valley coherence in a high-quality monolayer molybdenum diselenide
• The role of antisymmetric orbitals and electron-electron interactions on the two-particle spin and valley blockade in graphene double quantum dots
• Asymmetric Andreev resonant state with a magnetic exchange field in spin-triplet superconducting monolayer $Mo{S}_2$
• All-electrical valley filtering in graphene systems (II): Numerical study of electron transport in valley valves