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Surface codes: Towards practical large-scale quantum computation
The concept of the stabilizer, using two qubits, is introduced, and the single-qubit Hadamard, S and T operators are described, completing the set of required gates for a universal quantum computer.
Quantum ground state and single-phonon control of a mechanical resonator
This work shows that conventional cryogenic refrigeration can be used to cool a mechanical mode to its quantum ground state by using a microwave-frequency mechanical oscillator—a ‘quantum drum’—coupled to a quantum bit, which is used to measure the quantum state of the resonator.
Superconducting quantum circuits at the surface code threshold for fault tolerance
The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.
State preservation by repetitive error detection in a superconducting quantum circuit
The protection of classical states from environmental bit-flip errors is reported and the suppression of these errors with increasing system size is demonstrated, motivating further research into the many challenges associated with building a large-scale superconducting quantum computer.
Noise processes in nanomechanical resonators
Nanomechanical resonators can be fabricated to achieve high natural resonance frequencies, approaching 1 GHz, with quality factors in excess of 10^(4). These resonators are candidates for use as
Synthesizing arbitrary quantum states in a superconducting resonator
This work synthesizes the states using a superconducting phase qubit to phase-coherently pump photons into the resonator, making use of an algorithm that generalizes a previously demonstrated method of generating photon number (Fock) states in a resonator.
Microwave dielectric loss at single photon energies and millikelvin temperatures
The microwave performance of amorphous dielectric materials at very low temperatures and very low excitation strengths displays significant excess loss. Here, we present the loss tangents of some
Planar Superconducting Resonators with Internal Quality Factors above One Million
We describe the fabrication and measurement of microwave coplanar waveguide resonators with internal quality factors above 10 million at high microwave powers and over 1 million at low powers, with
Coherent Josephson qubit suitable for scalable quantum integrated circuits.
This work demonstrates a planar, tunable superconducting qubit with energy relaxation times up to 44 μs and finds a fine structure in the qubit energy lifetime as a function of frequency, indicating the presence of a sparse population of incoherent, weakly coupled two-level defects.