Journal Article

Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits

Dial, O. E., Yacoby, A., Harvey, S. P., Bluhm, H., Shulman, M. D., Umansky, V.

2012

Overview

Quantum computers have the potential to solve certain problems faster than classical computers. To exploit their power, it is necessary to perform interqubit operations and generate entangled states. Spin qubits are a promising candidate for implementing a quantum processor because of their potential for scalability and miniaturization. However, their weak interactions with the environment, which lead to their long coherence times, make interqubit operations challenging. We performed a controlled two-qubit operation between singlet-triplet qubits using a dynamically decoupled sequence that maintains the two-qubit coupling while decoupling each qubit from its fluctuating environment. Using state tomography, we measured the full density matrix of the system and determined the concurrence and the fidelity of the generated state, providing proof of entanglement.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Axes of rotation / Classical and quantum physics: mechanics and fields / Computers / Decoupling / Density / Dynamical systems / Electric fields / Electrons / electrostatic interactions / Electrostatics / Entanglement / Environment / Exact sciences and technology / Fluctuation / Magnetic fields / Microprocessors / Miniaturization / Physics / Quantum computation / Quantum computers / Quantum dots / Quantum entanglement / Quantum information / quantum mechanics / Quantum physics / Qubits (quantum computing) / Rotational states / Tomography