Long Coherence Times in Nuclear Spin-Free Vanadyl Qubits

Quantum coherence in a processable vanadyl complex: new tools for the search of molecular spin qubits

Department of Chemistry “Ugo Schiff”, U Florence, Via della Lastruccia 3-13, 50019 S Department of Chemistry, University of Tu Torino, Italy. E-mail: roberta.sessoli@uni. † Electronic supplementary information (E and methods. Additional characterizati (Fig. S1–S5); CWand pulsed EPR resul UHV deposition (Fig. S12–S14); calculate composition (Fig. S15). See DOI: 10.1039/ Cite this: Chem. Sci., 2...

Comparison of coherence times in three dc SQUID phase qubits

We report measurements of spectroscopic linewidth and Rabi oscillations in three thin-film dc SQUID phase qubits. One device had a 6-turn Nb loop, the second had a single-turn Al loop, and the third was a first order gradiometer formed from 6-turn wound and counter-wound Nb coils to provide isolation from spatially uniform flux noise. In the 6 7.2 GHz range, the spectroscopic coherence times fo...

Long coherence times for Rydberg qubits on a superconducting atom chip

Ultra-long distance interaction between spin qubits

We describe a method for implementing deterministic quantum gates between two spin qubits separated by centimeters. Qubits defined by the singlet and triplet states of two exchange coupled quantum dots have recently been shown to possess long coherence times. When the effective nuclear fields in the two asymmetric quantum dots are different, total spin will no longer be a good quantum number an...

Spectrum of the Nuclear Environment for GaAs Spin Qubits.

Using a singlet-triplet spin qubit as a sensitive spectrometer of the GaAs nuclear spin bath, we demonstrate that the spectrum of Overhauser noise agrees with a classical spin diffusion model over 6 orders of magnitude in frequency, from 1 mHz to 1 kHz, is flat below 10 mHz, and falls as 1/f^{2} for frequency f≳1  Hz. Increasing the applied magnetic field from 0.1 to 0.75 T suppresses electron-...