Wiring Up Superconducting Qubits

Process Tomography of Quantum Memory in a Josephson Phase Qubit coupled to a Two-Level State

A quantum computer will require quantum bits (qubits) with good coherence that can be coupled together to form logic gates. Superconducting circuits offer a novel solution since qubits can be connected in elaborate ways through simple wiring, much like that of conventional integrated circuits. However, this ease of coupling is offset by coherence times shorter than those observed in molecular a...

Generation of Three - Qubit Entangled States using Superconducting Phase Qubits : Supplementary Information

The phase qubits in this device were designed to have critical current I0 ≈ 2 μA, capacitance C ≈ 1 pF, and inductance L ≈ 720 pH. The coupling capacitance was Cc ≈ 15 pF, chosen to give coupling strength 2g/2π ≈ 15 MHz at a qubit frequency of 6 GHz. The fabrication process is the same as has been used in previous experiments[1], using a sapphire substrate with superconducting Al films, AlOx tu...

Viewpoint Superconducting Qubits Are Getting Serious

Bigger is better. Rather interestingly, this mantra appears true for superconducting quantum bits (qubits), which are considered one of the most attractive physical realizations of quantum logic elements for quantum information processing. Reporting in Physical Review Letters, Hanhee Paik, at Yale University, and colleagues demonstrate a novel implementation of a superconducting qubit with dime...

Development of Hardware for Scaling Up Superconducting Qubits and Simulation of Quantum Chaos

Direct measurement of the entanglement of two superconducting qubits via state tomography

The laws of quantum physics provide intriguing possibilities for a tremendous increase in speed compared to classical computation. Because this power is achieved through the controlled evolution of entangled quantum states, a clear demonstration of entanglement represents a key milestone towards the construction of a scalable quantum computer. Although entanglement can be inferred from simple e...