Circuit Quantum Electrodynamics - Yale School of Engineering ...

List of Symbols and Abbreviations 15
(Ic) Josephson critical current
(Jc) Josephson critical current density (per unit area)
(LJ) Josephson inductance
(LJ0) Josephson inductance in zero current limit
(LK) Kinetic inductance per unit length of the (superconducting) CPW
(Lm) Magnetic inductance per unit length of the CPW
(Ln) Effective resonator inductance for the n th cavity mode
(n) Average photon number in the cavity
(ncrit)
(nκ)
Number of photons before dispersive approximation fails to converge, ncrit =
∆ 2 /4g 2
Number of photons before second order term in dispersive Taylor expansion of
energy is comparable to cavity linewidth, nκ = κ∆3
2g 4
(ng) Gate polarization charge
(ns) Density of Cooper pairs
(nn) Density of quasiparticles
(Q) Cavity quality factor (Q = ωr/κ)
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Qint/ext Quality factor due to internal/external losses
(Qop) Operations quality factor, defined as number of oscillations in one decay time Top/T2
(Qφ) Pure dephasing quality factor
(Qres) Quality factor due to resistivity of CPW
(Qrad) Quality factor due to radiative losses
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qin/out
External inverse q factor, the external resonator quality factor is Qint = 1/q 2 in/out
(QED) quantum electrodynamics
(qubit) A quantum mechanical bit, referring to any quantum system with two levels
(RK) The resistance quantum (Von Klitzing constant) RK = h/e 2 ≈ 25.8 kΩ
(Rn) Resistance of tunnel junction in normal state