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Circuit Quantum Electrodynamics - Yale School of Engineering ...

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LIST OF FIGURES 9<br />

3.10 CPB circuit diagram / junction diagram . . . . . . . . . . . . . . . . . . . . . . . . . 62<br />

3.11 CPB energy levels and charge staircase . . . . . . . . . . . . . . . . . . . . . . . . . . 63<br />

3.12 Energy in two state approximation and fictitious field figure . . . . . . . . . . . . . . 64<br />

3.13 CPB Matrix elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65<br />

3.14 Split CPB sketch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67<br />

3.15 Dipole moment <strong>of</strong> the Cooper Pair Box . . . . . . . . . . . . . . . . . . . . . . . . . 70<br />

3.16 Measurement schematic and derivatives <strong>of</strong> CPB energy levels . . . . . . . . . . . . . 74<br />

3.17 State dependent transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75<br />

3.18 Q function <strong>of</strong> coherent states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76<br />

3.19 State dependent transmission with small phase shift . . . . . . . . . . . . . . . . . . 77<br />

3.20 Selecting ∆r for optimal SNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79<br />

3.21 Selecting κ/2χ for optimal SNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80<br />

4.1 Decoherence through gate voltage coupling circuit diagram and SV(ω) at different temperatures 84<br />

4.2 Quality factor <strong>of</strong> qubits coupled to transmission line and cavity . . . . . . . . . . . . 86<br />

4.3 CPB coupling to slotline mode in resonator . . . . . . . . . . . . . . . . . . . . . . . 87<br />

4.4 Flux noise circuit diagram and flux transition matrix elements . . . . . . . . . . . . 88<br />

4.5 Electric Field distribution in CPB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90<br />

4.6 Derivatives <strong>of</strong> energy with respect to gate charge . . . . . . . . . . . . . . . . . . . . 96<br />

4.7 Thermal Dephasing <strong>of</strong> the qubit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97<br />

4.8 Dephasing <strong>of</strong> qubit due to 1/f charge noise . . . . . . . . . . . . . . . . . . . . . . . 98<br />

4.9 Dephasing times due to flux and critical current noise . . . . . . . . . . . . . . . . . 101<br />

4.10 CPB energy bands at different EJ/EC ratios . . . . . . . . . . . . . . . . . . . . . . 104<br />

4.11 Anharmonicity vs. EJ/EC ratios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107<br />

4.12 Anharmonic barrier and dimensionless dephasing rates . . . . . . . . . . . . . . . . . 107<br />

4.13 Sketch and circuit diagram <strong>of</strong> the transmon . . . . . . . . . . . . . . . . . . . . . . . 108<br />

4.14 Analogy <strong>of</strong> transmon as quantum rotor . . . . . . . . . . . . . . . . . . . . . . . . . . 110<br />

4.15 Transmon matrix elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112<br />

4.16 Transmon dispersive couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114<br />

5.1 Resonator sample and gap capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . 120<br />

5.2 Optical lithography equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

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