Dual-Port Reflectometry Technique: Charge identification in nanoscaled single-electron transistors

Abstract

Radio-fRequency Reflectometry (RfR) is a technique that was developed to characterize the properties of transmission lines by observing reflected waveforms. today, it is widely used in a variety of applications, ranging from the detection of faulty wires in cables [1] and objects buried in the ground [2] to soil moisture detectors [3] and the measurement of dielectric properties of blood [4]. Recently, one important application of this technique, which requires a very small amount of applied power, was developed for the characterization of electronic nanostructures [5]. in this implementation, a microwave radio-frequency (Rf) signal is sent to a resonator coupled to the specimen to be studied. if in a specimen the change of some external parameter (e.g., gate voltage) leads to a change of an active [figure 1(a)] or a reactive (typically, capacitive) load [ figure 1(b)] to the resonator, the self-resonance is affected, resulting in a change of magnitude [figure 2(a)] and phase [figure 2(b)] of the reflected signal. if an impedance matching condition is achieved, the modification of the specimen parameter (e.g., the increase of its resistance) will lead to a very significant change in the reflection coefficient C [ figure 2(a)]. Here, we discuss two important applications of the RfR technique on nanoscale devices.first, RfR provides a method for fast (<100 ns) and broadband (in excess of 100 mHz) sensing of single-electron transistors (Sets) [5] and quantum point contacts (qPcs) [6], which are essential readout elements for promising new technologies such as spin quantum bits [7]- [9]. By contrast, the traditional methods of probing these types of devices by measuring changes in their conductance or resistance suffer from very limited bandwidth (<1 mHz) due to the high impedance of the devices and parasitic input capacitance of the sensing amplifier. in an

Single donor electronics and quantum functionalities with advanced CMOS technology

“…The confinement by trench isolation or dielectrics is also very ben eficial for density and integration compared to electrostatic confinement which requires too many gates per bit. Finally the very good coupling of our quantum dots with their control gate enables radiofrequency reflectometry on gates to be used as efficient detectors for fast qubit readout [45,[84][85][86][87].…”

Level Spectrum and Charge Relaxation in a Silicon Double Quantum Dot Probed by Dual-Gate Reflectometry

“…Two lumped-element resonators, S 1 and S 2 , are connected to G 1 and G 2 , respectively. Each resonator is composed of a surface-mount inductor (nominal inductances: L 1 = 270 nH and L 2 = 390 nH for S 1 and S 2 , respectively) and the parasitic capacitance C p at the corresponding gate [7][8][9]25 [see Fig. 1b)].…”