Ultrafast optical control of entanglement between two quantum dot spins
arXiv:1007.3733 · doi:10.1038/nphys1863
Abstract
The interaction between two quantum bits enables entanglement, the two-particle correlations that are at the heart of quantum information science. In semiconductor quantum dots much work has focused on demonstrating single spin qubit control using optical techniques. However, optical control of entanglement of two spin qubits remains a major challenge for scaling from a single qubit to a full-fledged quantum information platform. Here, we combine advances in vertically-stacked quantum dots with ultrafast laser techniques to achieve optical control of the entangled state of two electron spins. Each electron is in a separate InAs quantum dot, and the spins interact through tunneling, where the tunneling rate determines how rapidly entangling operations can be performed. The two-qubit gate speeds achieved here are over an order of magnitude faster than in other systems. These results demonstrate the viability and advantages of optically controlled quantum dot spins for multi-qubit systems.
24 pages, 5 figures
References in corpus (14)
- Driven coherent oscillations of a single electron spin in a quantum dot
- Demonstration of Two-Qubit Algorithms with a Superconducting Quantum Processor
- Scalable quantum register based on coupled electron spins in a room temperature solid
- Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
- Generation and transfer of single photons on a photonic crystal chip
- Optically generated 2-dimensional photonic cluster state from coupled quantum dots
- Fast optical preparation, control and read-out of single quantum dot spin
- Prospects for measurement-based quantum computing with solid state spins
- Theory of fast optical spin rotation in a quantum dot based on geometric phases and trapped states
- Optically Probing Spin and Charge Interactions in an Tunable Artificial Molecule
- Quantum computers based on electron spins controlled by ultra-fast, off-resonant, single optical pulses
- Quantum Computing with Spin Qubits Interacting Through Delocalized Excitons: Overcoming Hole Mixing
- Coherent optical manipulation of triplet-singlet states in coupled quantum dots
- Optically induced spin gates in coupled quantum dots using the electron-hole exchange interaction