arXiv subjects

Matthias Meschke

Publications and source records attributed to Matthias Meschke.

11 recordsLinked to original sources

arXiv2016

Traceable Coulomb Blockade Thermometry

We present a measurement and analysis scheme for determining traceable thermodynamic temperature at cryogenic temperatures using Coulomb blockade thermometry. The uncertainty of the electrical measurement is improved by utilizing two sampling digital voltmeters instead of the traditional lock-in technique. The remaining uncertainty is dominated by that of the numerical analysis of the measurement data. Two analysis methods are demonstrated: numerical fitting of the full conductance curve and measuring the height of the conductance dip. The complete uncertainty analysis shows that using either analysis method the relative combined standard uncertainty (k = 1) in determining the thermodynamic temperature in the temperature range from 20 mK to 200 mK is below 0.5 %. In this temperature range, both analysis methods produced temperature estimates that deviated from 0.39 % to 0.67 % from the reference temperatures provided by a superconducting reference point device calibrated against the Provisional Low Temperature Scale of 2000.

physics.ins-det↗

arXiv2015

A robust platform cooled by superconducting electronic refrigerators

A biased tunnel junction between a superconductor and a normal metal can cool the latter electrode. Based on a recently developed cooler with high power and superior performance, we have successfully integrated it with a dielectric silicon nitride membrane, and cooled phonons from 305 mK down to 200 mK. Without perforation and covered under a thin alumina layer, the membrane is rigorously transformed into a cooling platform that is robust and versatile for multiple practical purposes. We discuss our results and possibilities to further improve the device.

cond-mat.mes-hall↗

arXiv2013

Non-hysteretic superconducting quantum interference proximity transistor with enhanced responsivity

This letter presents fabrication and characterization of an optimized SQUIPT (superconducting quantum interference proximity transistor). The present device, characterized with reduced tunnel junction area and shortened normal-metal section, demonstrates no hysteresis at low temperatures as we increased the Josephson inductance of the weak link by decreasing its cross section. It has consequently almost an order of magnitude improved magnetic field responsivity as compared to the earlier design. The modulation of both the current and the voltage across the junction have been measured as a function of magnetic flux piercing the superconducting loop.

cond-mat.supr-con↗

arXiv2012

Micrometre-scale refrigerators

A superconductor with a gap in the density of states or a quantum dot with discrete energy levels is a central building block in realizing an electronic on-chip cooler. They can work as energy filters, allowing only hot quasiparticles to tunnel out from the electrode to be cooled. This principle has been employed experimentally since the early 1990s in investigations and demonstrations of micrometre-scale coolers at sub-kelvin temperatures. In this paper, we review the basic experimental conditions in realizing the coolers and the main practical issues that are known to limit their performance. We give an update of experiments performed on cryogenic micrometre-scale coolers in the past five years.

cond-mat.mes-hall↗

arXiv2010

Comparison of Coulomb Blockade Thermometers with the International Temperature Scale PLTS-2000

The operation of the primary Coulomb blockade thermometer (CBT) is based on a measurement of bias voltage dependent conductance of arrays of tunnel junctions between normal metal electrodes. Here we report on a comparison of a CBT with a high accuracy realization of the PLTS-2000 temperature scale in the range from 0.008 K to 0.65 K. An overall agreement of about 1% was found for temperatures above 0.25 K. For lower temperatures increasing differences are caused by thermalization problems which are accounted for by numerical calculations based on electron-phonon decoupling.

cond-mat.mes-hall↗

arXiv2009

Quantized current of a hybrid single-electron transistor with superconducting leads and a normal-metal island

We discuss the operation of the superconductor - insulator - normal-metal - insulator - superconductor (SINIS) turnstile. This voltage-biased hybrid single-electron transistor (SET) provides current quantization even with only one radio-frequency (rf) control parameter, namely the gate voltage of the single island. We give an overview of the main error mechanisms of the turnstile and consider its feasibility as a quantum current standard. We also present experimental results of pumping with the SINIS structure which show decreased leakage current compared to earlier measurements with the opposite NISIN structure.

cond-mat.mes-hall↗

arXiv2009

Electronic Refrigeration at the Quantum Limit

We demonstrate quantum limited electronic refrigeration of a metallic island in a low temperature micro-circuit. We show that matching the impedance of the circuit enables refrigeration at a distance, of about 50 um in our case, through superconducting leads with a cooling power determined by the quantum of thermal conductance. In a reference sample with a mismatched circuit this effect is absent. Our results are consistent with the concept of electromagnetic heat transport. We observe and analyze the crossover between electromagnetic and quasiparticle heat flux in a superconductor.

cond-mat.mes-hall↗

arXiv2008

Primary tunnel junction thermometry

We describe the concept and experimental demonstration of primary thermometry based on a four probe measurement of a single tunnel junction embedded within four arrays of junctions. We show that in this configuration random sample specific and environment-related errors can be avoided. This method relates temperature directly to Boltzmann constant, which will form the basis of the definition of temperature and realization of official temperature scales in the future.

cond-mat.mes-hall↗

arXiv2007

Hybrid single-electron transistor as a source of quantized electric current

The basis of synchronous manipulation of individual electrons in solid-state devices was laid by the rise of single-electronics about two decades ago. Ultra-small structures in a low temperature environment form an ideal domain of addressing electrons one by one. A long-standing challenge in this field has been the realization of a source of electric current that is accurately related to the operation frequency $f$. There is an urgent call for a quantum standard of electric current and for the so-called metrological triangle, where voltage from Josephson effect and resistance from quantum Hall effect are tested against current via Ohm's law for a consistency check of the fundamental constants of Nature, $\hbar$ and $e$. Several attempts to create a metrological current source that would comply with the demanding criteria of extreme accuracy, high yield, and implementation with not too many control parameters have been reported. However, no satisfactory solution exists as yet despite many ingenious achievements that have been witnessed over the years. Here we propose and prove the unexpected concept of a hybrid metal-superconductor turnstile in the form of a one-island single-electron transistor with one gate, which demonstrates robust current plateaus at multiple levels of $ef$ within the uncertainty of our current measurement. Our theoretical estimates show that the errors of the present system can be efficiently suppressed by further optimizations of design and proper choice of the device parameters and therefore we expect it to eventually meet the stringent specifications of quantum metrology.

cond-mat.mes-hall↗

arXiv2007

Heat Transistor: Demonstration of Gate-Controlled Electron Refrigeration

We present experiments on a superconductor-normal metal electron refrigerator in a regime where single-electron charging effects are significant. The system functions as a heat transistor, i.e., the heat flux out from the normal metal island can be controlled with a gate voltage. A theoretical model developed within the framework of single-electron tunneling provides a full quantitative agreement with the experiment. This work serves as the first experimental observation of Coulombic control of heat transfer and, in particular, of refrigeration in a mesoscopic system.

cond-mat.mes-hall↗

arXiv2004

Study of Field-Induced Magnetic Order in Singlet-Ground-State Magnet CsFeCl$_3$

The field-induced magnetic order in the singlet-ground-state system CsFeCl$_3$ has been studied by measuring magnetization and neutron diffraction. The field dependence of intensity for the neutron magnetic reflection has clearly demonstrated that the field-induced ordered phase is described by the order parameter $ $. A condensate growth of magnons is investigated through the temperature dependence of $M_z$ and $M_{\perp}$, and this ordering is discussed in the context of a magnon Bose-Einstein condensation. Development of the coherent state and the static correlation length has been observed in the incommensurate phase in the field region of $5 < H < 6$ T at 1.8 K. At $H > H_{\rm c}$, a satellite peak was found in coexistence with the commensurate peak at the phase boundary around 10 T, which indicates that the tilt of the c-axis would be less than $\sim 0.5^{\circ}$ in the whole experiments.

cond-mat.mtrl-sci↗