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

• ; Kalman filter; Lyapunov filter; digital signal processing; field-programmable gate array (FPGA); Introduction Atomic force microscopy (AFM) [1] has enabled innovation in nanoscale engineering since it was invented in 1986 by Binnig and co-workers. Atomic-scale topographical resolution is achieved by

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

• same digital signal-processing platform to conduct quantitative and direct performance comparisons. We also present the result of high-speed FM-AFM imaging of calcite dissolution with atomic-scale resolution to demonstrate the applicability of the proposed PLL design to practical experiments

• parameters were individually optimized for a 3 MHz input signal and 100 MHz clock frequency for digital signal processing. As explained in the Experimental section in detail, we implemented these parameters based on objective criteria to achieve fair comparison. For a LPF (Figure 2a(iii)), the latency is 38

• the following equation: Thus, we fitted the phase curves using this equation and estimated τd, which is given in Table 1 and Table 2. The latency is mainly caused by the ADC/DAC and digital signal processing in the FPGA. Since the former should be constant, the difference originates from the signal

Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials

• Daniela Dragoman

Beilstein J. Nanotechnol. 2018, 9, 1828–1833, doi:10.3762/bjnano.9.174

• logic circuits. As mentioned already, the discrete Fourier transform is essential in digital signal processing [7] and computing algorithms [8], the discrete FrFT being not so much studied yet. However, it could become interesting in the future. It should be noted that discretized input and/or output

• signal processing [7] as well as in many quantum computing algorithms [8], via the discrete Fourier transform. Moreover, the proposed configuration allows the implementation of a FrFT with a tunable order in atomically thin materials in which the charge carriers obey either the Schrödinger equation (as

• in a direct way/in one step an integral transform of a quantum wave function of ballistic electrons, namely the fractional Fourier transform (FrFT); this configuration is in fact a FrFT coprocessor. In particular, the Fourier transform, which is a special case of the FrFT, is of interest in digital

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

• ; digital signal processing; field-programmable gate array (FPGA); high-speed; Lyapunov filter; multifrequency; Introduction Atomic force microscopy (AFM) [1] has been integral in the field of nanoscale engineering since its invention in 1986 by Binnig et al. By sensing microcantilever tip–sample

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

• constant-height mode. Keywords: amplitude estimation; atomic force microscopy; amplitude modulation; digital signal processing; field-programmable gate array; Introduction Amplitude modulation is one of the oldest forms of modulation in analog communication systems, mostly due to its simplicity of

• a fair comparison, a widely used digital signal processing system (LabVIEW) is used and the implementations are unified to a common sample rate. The performance metrics are tracking bandwidth, implementation complexity, sensitivity to other frequency components and total integrated noise of the

• -running sample rate achieved by the digital signal processing system. Where applicable, latencies arising from fixed time-delays in the implementation of the methods are highlighted. The tracking bandwidth is defined as the frequency f−3dB, at which the amplitude estimate drops by −3 dB. This figure of

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• estimated to be approximately 10 µm. Using digital signal processing in HIM, the image remains sharp unless the diameter of the beam is larger than the pixel size in the image. From the width of the image field of view (2.5 μm) and the number of acquisition points 1000 × 1000, the pixel size was calculated

An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

• Elnaz Akbari,
• Vijay K. Arora,
• Aria Enzevaee,
• Mohamad. T. Ahmadi,
• Mehdi Saeidmanesh,
• Mohsen Khaledian,
• Hediyeh Karimi and
• Rubiyah Yusof

Beilstein J. Nanotechnol. 2014, 5, 726–734, doi:10.3762/bjnano.5.85

• in the I–V characteristics of graphene/CNT. Operational amplifiers amplify these signals that can be converted to digital format for digital signal processing. FET-based structure As presented in Figure 2, the structure of the proposed gas sensors that use CNT/graphene as the conducting channel looks

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

• microscope (UHV-VT-AFM). It is operated by a Nanonis scanning probe microscopy (SPM) controller entirely based on digital signal processing (DSP). The probe that was used in these experiments is a platinum-iridium coated Nanosensors Point Probe Plus EFM tip with a spring constant between 1 and 3 N/m. Its