Improved superconducting qubit coherence using titanium nitride

Improved superconducting qubit readout by qubit-induced nonlinearities.

In dispersive readout schemes, qubit-induced nonlinearity typically limits the measurement fidelity by reducing the signal-to-noise ratio (SNR) when the measurement power is increased. Contrary to seeing the nonlinearity as a problem, here we propose to use it to our advantage in a regime where it can increase the SNR. We show analytically that such a regime exists if the qubit has a many-level...

Anomalous response of superconducting titanium nitride resonators to terahertz radiation

Qubit lattice coherence induced by electromagnetic pulses in superconducting metamaterials

Quantum bits (qubits) are at the heart of quantum information processing schemes. Currently, solid-state qubits, and in particular the superconducting ones, seem to satisfy the requirements for being the building blocks of viable quantum computers, since they exhibit relatively long coherence times, extremely low dissipation, and scalability. The possibility of achieving quantum coherence in ma...

Scalable superconducting qubit circuits using dressed states

Yu-xi Liu, C. P. Sun, and Franco Nori Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-0198, Japan CREST, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan Institute of Theoretical Physics, The Chinese Academy of Sciences, Beijing 100080, China Center for Theoretical Physics, Physics Department, and Center for t...

Probing the quantum coherence of a nanomechanical resonator using a superconducting qubit II: Implementation

We describe a possible implementation of the nanomechanical quantum superposition generation and detection scheme described in the preceding, companion paper [Armour A D and Blencowe M P 2008 New. J. Phys. XX XXX]. The implementation is based on the circuit quantum electrodynamics (QED) set-up, with the addition of a mechanical degree of freedom formed out of a suspended, doublyclamped segment ...