A5091791594- Mechanical and Optical Resonators
- Carbon Nanotubes in Composites
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Calibration and Measurement Techniques
- Quantum Information and Cryptography
- Superconducting and THz Device Technology
- Force Microscopy Techniques and Applications
- Nanotechnology research and applications
- Analog and Mixed-Signal Circuit Design
- Advanced Sensor Technologies Research
- Advanced Thermodynamic Systems and Engines
- Graphene research and applications
- Characterization and Applications of Magnetic Nanoparticles
- Quantum optics and atomic interactions
- Advanced Memory and Neural Computing
- Scientific Measurement and Uncertainty Evaluation
- Advanced MEMS and NEMS Technologies
- Electrochemical Analysis and Applications
- Mechanical Engineering and Vibrations Research
- Mechanics and Biomechanics Studies
- Molecular Junctions and Nanostructures
- Advancements in Semiconductor Devices and Circuit Design
- Geomagnetism and Paleomagnetism Studies
- Electron and X-Ray Spectroscopy Techniques
VTT Technical Research Centre of Finland
2021
Bluefors (Finland)
2021
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2016
Tieto (Finland)
2013
Helsinki Institute of Physics
2002
We have measured IV-curves of multiwalled carbon nanotubes using end contacts. At low voltages, the tunneling conductance obeys non-Ohmic power law, which is predicted both by Luttinger liquid and environment-quantum-fluctuation theories. However, at higher voltages we observe a crossover to Ohm's law with Coulomb-blockade offset, agrees theory, but cannot be explained Luttinger-liquid theory. From high-voltage determine transmission line parameters nanotubes.
We demonstrate high-contrast state detection of a superconducting flux qubit. Detection is realized by probing the microwave transmission nonlinear resonator, based on SQUID. Depending driving strength detector can be operated in monostable or bistable mode. The operation combines high-sensitivity with intrinsic latching. measured contrast Rabi oscillations as high 87%; missing 13%, only 3% loss unaccounted for. Experiments involving two consecutive pulses are consistent preparation qubit...
The effective capacitance has been measured in the split Cooper-pair box (CPB) over its phase-gate bias plane. Our low-frequency reactive measurement scheme allows us to probe purely capacitive susceptibility due CPB band structure. data are quantitatively explained using parameters determined independently by spectroscopic means. In addition, we show practice that method offers an efficient way do nondemolition readout of quantum state.
We positioned semiconducting multiwalled carbon nanotube, using an atomic force microscope, between two gold electrodes at SiO2 surface. Transport measurements exhibit single-electron effects with a charging energy of 24 K. Using the Coulomb staircase model, capacitances and resistances tube can be characterized in detail.
Abstract Cooling nanoelectronic structures to millikelvin temperatures presents extreme challenges in maintaining thermal contact between the electrons device and an external cold bath. It is typically found that when nanoscale devices are cooled ∼10 mK significantly overheated. Here we report cooling of Coulomb blockade thermometers below 4 mK. The low operating temperature attributed optimized design incorporates fins with a high electron–phonon coupling on-chip electronic filters,...
We present a cryogenic microwave noise source with characteristic impedance of 50 Ω, which can be installed in coaxial line cryostat. The bath temperature the is continuously variable between 0.1 K and 5 without causing significant back-action heating on sample space. As proof-of-concept experiment, we perform Y-factor measurements an amplifier cascade that includes traveling wave parametric commercial high electron mobility transistor amplifier. observe system temperatures as low 680−200+20...
We have developed a scheme to manipulate metallic aerosol particles on silicon dioxide substrates using an atomic force microscope. The method utilizes the noncontact mode both for locating and moving nanoparticles of size 10–100 nm. main advantage our technique is possibility “seeing” particle in real time. Our avoids well sticking problems that typically hamper manipulation contact mode.
We have analyzed a radio-frequency single-electron-transistor (RF-SET) circuit that includes high-electron-mobility-transistor (HEMT) amplifier, coupled to the (SET) via an impedance transformer. consider how power is transferred between different components of circuit, model noise components, and analyze operating conditions practical importance. The results are compared with experimental data on SETs. Good agreement obtained our results. Our analysis shows, also, biggest improvement...
Nomography is considered a branch of mathematics introduced by Maurice d’Ocagne in 1884 France. The past century saw nomography grow as graphical computing method used scientists and engineers wishing to solve complex problems practical precision. Even though has declined with the introduction calculators computers, it still offers potential an educational setting. recent development open-source software helping promote use nomograms among scholars engineering courses who are aware...
A two-channel AC voltage source based on digital synthesis is reported. We present measurement results of some the key properties at 1 kHz with applications like impedance bridges in mind. Measurements show that amplitude ratio channels has a stability (Allan standard deviation) one part 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> for 30 min measurement. The phase difference between also stable within 0.1 μrad.
A three-terminal nanotube device was fabricated from two multiwalled nanotubes by pushing one on top of the other using an atomic-force microscope. The lower nanotube, with gold contacts at both ends, acted as central island a single-electron transistor while upper functioned gate electrode. Coulomb blockade oscillations were observed sub-Kelvin temperatures. voltage noise (SET) gain dependent in conventional SETs. charge sensitivity 10 Hz 6×10−4 e/Hz.
We demonstrate a sensitive method of charge detection based on radio-frequency readout the Josephson inductance superconducting single-electron transistor. Charge sensitivity $1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}\text{ }e/\sqrt{\mathrm{H}\mathrm{z}}$, limited by preamplifier, is achieved in an operation mode which takes advantage nonlinearity potential. Owing to reactive readout, our setup has more than 2 orders magnitude lower dissipation existing electrometry. With...
We show that it is possible to construct low-noise single-electron transistors (SETs) using free-standing multiwalled carbon nanotubes. The 1/fα-noise of our devices, 6×10−6e/Hz at 45 Hz, close in the performance best metallic SETs today.
Abstract We demonstrate significant cooling of electrons in a nanostructure below 10 mK by demagnetisation thin-film copper on silicon chip. Our approach overcomes the typical bottleneck weak electron-phonon scattering coupling directly to bath refrigerated nuclei, rather than via phonons host lattice. Consequently, becomes an advant- age. It allows be cooled for experimentally useful period time temperatures colder dilution refrigerator platform, incoming electrical connections, and There...
We present a measurement and analysis scheme for determining traceable thermodynamic temperature at cryogenic temperatures using Coulomb blockade thermometry. The uncertainty of the electrical is improved by utilizing two sampling digital voltmeters instead traditional lock-in technique. remaining dominated that numerical data. Two methods are demonstrated: fitting full conductance curve measuring height dip. complete shows either method relative combined standard (k = 1) in range from 20 mK...
We discuss how a single Cooper-pair transistor may be used to detect the superconducting phase difference by using dependence of input capacitance from gate ground. The proposed device has low power dissipation because its operation is in principle free quasiparticle generation. According sensitivity estimates, for efficient qubit readout galvanically isolated and symmetrized circuit.
We have constructed a noise measurement setup for high impedance carbon nanotube samples. Our setup, working in the frequency range of 600 – 900 MHz, takes advantage fact that shot power is reasonably large sources so relatively large, fixed non‐matching conditions can be tolerated.