Noise in the Coulomb blockade electrometer

Abstract

We have measured the noise of a Coulomb blockade electrometer. Below 100 Hz, the noise referred to the input charge has a 1/f power spectrum with a charge noise of 3×10−4 e/√Hz and an energy sensitivity EN of 3×104 ℏ at 10 Hz. The 1/f noise probably results from the stochastic occupation of charge traps which could in principle be eliminated. The theoretical noise floor is set by shot noise, and indirect measurements show that this contribution to EN can be as small as 1.5 ℏ, suggesting that the electrometer will be a quantum limited amplifier if the 1/f noise can be eliminated.

Josephson charge qubits: a brief review

“…The parameter α has been obtained from the dc transport measurements for a device with essentially same geometry and fabrication process, and has been found to be α = (1.3 × 10 −3 e) 2 . This value is consistent with what was reported in other works [43][44][45], and also with the value derived from T 2 . Figure 6 summarizes the reduced noise spectrum S E derived from the measured 1 according to Eq.…”

“…1/ f charge noise is very common in single-electron devices and is usually attributed to random motion of charges either in the substrate or the junction barrier, although the exact mechanism is still not known [43][44][45]. Indeed, the sample studied here also showed 1/ f noise when the dc current through the probe junction was measured.…”

Non-Gaussian signatures and collective effects in charge noise affecting a dynamically decoupled qubit

“…Working at low temperatures as compared with the TLF level splitting results in longer stays in the lower state. Such asymmetric telegraphic signals were observed in various systems, including tunnel junctions, 40 and a Single Electron Tunneling electrometer. 41 Furthermore, our general results for asymmetric TLFs may be relevant in explaining temperature-dependent noise spectroscopy measurements that were recently performed on S − T 0 qubits.…”

A quantitative study of bias triangles presented in chemical potential space

“…These occupation numbers only change when a gate voltage(s) is changed in such a way that the chemical potential of a dot is lowered below that of the leads µ S(D) or that of the neighboring dot. These boundaries between stable charge regions can be experimentally mapped out by measuring a response sensitive to charge reconfigurations in the device, such as a nearby quantum point contact [9] or single electron transistor [10,11] or, as recently shown, the dispersive response of one of the device gates [12]. In this manuscript, however, we measured the transport through the device.…”