Cryogenic low-noise amplifiers for measurements with superconducting detectors

• Ilya L. Novikov,
• Boris I. Ivanov,
• Dmitri V. Ponomarev and
• Aleksey G. Vostretsov

Beilstein J. Nanotechnol. 2020, 11, 1316–1320, doi:10.3762/bjnano.11.115

• density of 0.33 nV/ with a 1/f flicker noise corner frequency of 0.1 Hz but there is no information about gain and noise performance at 77 K. Moreover, it would be useful to compare room-temperature results of BJT-based differential amplifiers with results obtained at 77 K. Also, modern cryogenic

An atomic force microscope integrated with a helium ion microscope for correlative nanoscale characterization

• Santiago H. Andany,
• Gregor Hlawacek,
• Stefan Hummel,
• Charlène Brillard,
• Mustafa Kangül and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2020, 11, 1272–1279, doi:10.3762/bjnano.11.111

• to a spring-loaded kinematic mount. Operating the AFM inside the HIM chamber has drawbacks regarding resolution and noise performance. Ideally, the mechanical loop between the cantilever probe and the sample needs to be compact and stiff for optimal AFM performance. The mechanical loop for the

A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• [28][31]. Motivated by improving high-speed MF-AFM demodulation capabilities, a multifrequency Kalman filter was developed [32]. It outperformed a commercially available lock-in amplifier in terms of both tracking bandwidth and noise performance. However, a major disadvantage of the Kalman filter is

• are able to maintain very high tracking bandwidths, achieving single-cycle convergence (f−3dB ≈ fi) with optimal noise performance. Results and Discussion Experimental setup The multifrequency demodulation techniques detailed in the previous section were implemented on a Xilinx Kintex-7 KC705

• benefit for widely spaced signals. At high tracking bandwidths, a closed-loop method is recommended as they achieve single-cycle convergence (f−3dB ≈ fi) with optimal noise performance. Also, each channel has the added benefit of zeroing other resonant modes. The Lyapunov filter and direct-design method

Quantitative comparison of wideband low-latency phase-locked loop circuit designs for high-speed frequency modulation atomic force microscopy

• Kazuki Miyata and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2018, 9, 1844–1855, doi:10.3762/bjnano.9.176

• vibration and that the noise generated inside the PLLs is negligible. The cut-off frequencies of the measured spectra correspond to the bandwidths listed in Table 1 and Table 2, as expected from the basic PLL principle. Overall, these results confirm that the developed PLLs can provide the optimal noise

• performance in FM-AFM experiments performed in liquids for both the NCH and USC cantilevers. High-speed FM-AFM imaging with true atomic resolution To investigate the applicability of the developed S-PLL to high-speed atomic-resolution imaging in a liquid, we imaged calcite dissolution in water. Figure 9a

Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert,
• Michael R. P. Ragazzon and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2018, 9, 490–498, doi:10.3762/bjnano.9.47

• , previous work by the authors includes a multifrequency Kalman filter [24]. It was shown to outperform a commercially available LIA in terms of both tracking bandwidth and noise performance. However, a major disadvantage of the Kalman filter is the large computational expense of each additional frequency

• the noise performance has been shown to be a function of the tracking bandwidth [19]. The lock-in amplifier is the state-of-the-art multifrequency method due to its strong off-mode rejection, however it can not achieve the same speed as the Lyapunov filter due to post-mixing filtering [19]. As the

A review of demodulation techniques for amplitude-modulation atomic force microscopy

• Michael G. Ruppert,
• David M. Harcombe,
• Michael R. P. Ragazzon,
• S. O. Reza Moheimani and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2017, 8, 1407–1426, doi:10.3762/bjnano.8.142

• generate a harmonic at fc, which is the reason why lock-in amplifiers should always be AC-coupled. The order and cut-off frequency of the low-pass filter directly determines the tracking bandwidth and hence the noise performance. For instance, in order to limit the ripple to 1% of the signal, a −40 dB

• evident in Figure 13a. The flat region around the modeled frequency where the amplitude is within −3 dB corresponds to twice the tracking bandwidth. The tuning for the Kalman filter is described in Appendix C. Noise evaluation In order to determine the noise performance, the RMS noise of the amplitude

• filter, despite being of low order, show excellent noise performance over the entire bandwidth of interest. The feasible tracking bandwidth range for each demodulator can be read from Figure 16. The sensitivity to other frequency components is assessed by the off-mode rejection experiment, which measures

Multimodal cantilevers with novel piezoelectric layer topology for sensitivity enhancement

• Steven Ian Moore,
• Michael G. Ruppert and
• Yuen Kuan Yong

Beilstein J. Nanotechnol. 2017, 8, 358–371, doi:10.3762/bjnano.8.38

• fashion for each mode. Cantilever dimensions shown in Figure 1. Sensitivities of the reference cantilever C1 compared to the cantilevers with optimal transducer topologies. Parameters of the identified transfer functions around the modes. Sensor sensitivities and noise performance of non-optimized and

Understanding interferometry for micro-cantilever displacement detection

• Alexander von Schmidsfeld,
• Tobias Nörenberg,
• Matthias Temmen and
• Michael Reichling

Beilstein J. Nanotechnol. 2016, 7, 841–851, doi:10.3762/bjnano.7.76

• small mirror area. Such a system is susceptible to misalignment resulting in increased optical loss in the cavity and a strongly reduced signal-to-noise performance. In a previous publication, we have shown that using the bare, cleaved fiber end allows one to change the characteristics of the

• cantilever and the noise performance of the system. Measurements are performed with the balanced detector to yield the best possible noise performance. To characterize the cantilevers and the noise performance of the detection system, we use well-established methods based on the spectral analysis of

• explored, we find that opto-mechanical coupling is apparently the limiting factor for the noise performance of our system. In the distance regime between Fabry–Pérot and Michelson operation (200 to 350 μm) the modulation of the interferometer signal is too small to detect a meaningful cantilever

High-bandwidth multimode self-sensing in bimodal atomic force microscopy

• Michael G. Ruppert and
• S. O. Reza Moheimani

Beilstein J. Nanotechnol. 2016, 7, 284–295, doi:10.3762/bjnano.7.26

• higher mode which was already noticed from Figure 6c. On the fifth mode, the strain sensor produces the same output for a much smaller deflection, yielding a much larger sensitivity. Noise analysis The noise performance of cantilever deflection sensors used in dynamic AFM is commonly evaluated with the

• sample showing amplitude in [nm] and phase in [°] using (a)–(e) the OBD sensor and (f)–(j) the charge sensor. Note the contrast reversal of the amplitude of the fifth mode between the OBD and charge sensor. Parameters of the fixed structure model. Noise performance of OBD and charge sensor

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• , in addition to avoiding divisions by small signals, the Kalman filter improves noise performance by bandwidth adjustments. For normalised closed-loop bandwidths ≤ 1, the bandwidth is adjusted following (Figure 7b). Larger bandwidths are not desired, since they would counteract the lock-in lowpass

• dynamic AFM modes. Precise knowledge of their frequency dependence in low and high Q environments is not only neccessary for accurate open-loop KFM techniques, but also offers a direct approach to noise performance and optimisation of frequency modulated KFM [19]. For example, ωm should ideally be chosen

High-frequency multimodal atomic force microscopy

• Adrian P. Nievergelt,
• Jonathan D. Adams,
• Pascal D. Odermatt and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2014, 5, 2459–2467, doi:10.3762/bjnano.5.255

• our system for noise performance will decrease the baseline noise value further [35]. Dissipation imaging Bimodal imaging The capability for clean, high-frequency cantilever excitation, and low-noise, high-frequency deflection readout provide a powerful platform for extending multifrequency techniques

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• to a complete suppression of hysteresis and an approximate 9-fold improvement in the noise performance [36]. Suspended devices are also attractive for self-heated, low-power architectures [30]. There are still several challenges to be addressed, particularly in the large-scale fabrication of these

• noise performance, gas sensor products operating at extremely low powers can be envisioned. Compared to nanotube networks employing the same number of nanotubes, a better signal-to-noise ratio, lower power and smaller sizes could then be achieved. In this direction, suspended gas sensors appear to be

• the preferred architecture due to the low-power recovery and low noise performance. Examples of different back-gated device architectures employed for carbon nanotube field-effect transistor gas sensors. a) On-substrate, unpassivated devices, where the entire device is exposed to the analyte. The

Noise performance of frequency modulation Kelvin force microscopy

• Heinrich Diesinger,
• Dominique Deresmes and
• Thierry Mélin

Beilstein J. Nanotechnol. 2014, 5, 1–18, doi:10.3762/bjnano.5.1

• Heinrich Diesinger Dominique Deresmes Thierry Melin Institut d’Electronique, Microélectronique et Nanotechnologie (IEMN), CNRS UMR 8520, CS 60069, Avenue Poincaré, 59652 Villeneuve d’Ascq, France 10.3762/bjnano.5.1 Abstract Noise performance of a phase-locked loop (PLL) based frequency modulation

• Kelvin force microscope (FM-KFM) is assessed. Noise propagation is modeled step by step throughout the setup using both exact closed loop noise gains and an approximation known as “noise gain” from operational amplifier (OpAmp) design that offers the advantage of decoupling the noise performance study

• factors for both cases are then established, suggesting how to tackle noise performance by probe design. Typical merit factors of common probe types are compared. This comprehensive study is an encouraging step toward a more integral performance assessment and a remedy against focusing on single aspects

Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

• Jannis Lübbe,
• Matthias Temmen,
• Sebastian Rode,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 32–44, doi:10.3762/bjnano.4.4

• and good noise performance, while the larger and softer cantilever D 5 is the better choice for slower measurements with best possible noise performance. Conclusion We investigated the relation between the displacement noise in NC-AFM measurements and the corresponding frequency-shift noise at the