TY - JOUR AU - Fehérvári, János Gergő AU - Balogh, Zoltán AU - Török, Tímea Nóra AU - Halbritter, András Ernő TI - Noise tailoring, noise annealing, and external perturbation injection strategies in memristive Hopfield neural networks JF - APL machine learning. J2 - APL mach. learn. VL - 2 PY - 2024 IS - 1 PG - 15 SN - 2770-9019 DO - 10.1063/5.0173662 UR - https://m2.mtmt.hu/api/publication/34536907 ID - 34536907 AB - The commercial introduction of a novel electronic device is often preceded by a lengthy material optimization phase devoted to the suppression of device noise as much as possible. The emergence of novel computing architectures, however, triggers a paradigm shift in noise engineering, demonstrating that non-suppressed but properly tailored noise can be harvested as a computational resource in probabilistic computing schemes. Such a strategy was recently realized on the hardware level in memristive Hopfield neural networks, delivering fast and highly energy efficient optimization performance. Inspired by these achievements, we perform a thorough analysis of simulated memristive Hopfield neural networks relying on realistic noise characteristics acquired on various memristive devices. These characteristics highlight the possibility of orders of magnitude variations in the noise level depending on the material choice as well as on the resistance state (and the corresponding active region volume) of the devices. Our simulations separate the effects of various device non-idealities on the operation of the Hopfield neural network by investigating the role of the programming accuracy as well as the noise-type and noise amplitude of the ON and OFF states. Relying on these results, we propose optimized noise tailoring and noise annealing strategies, comparing the impact of internal noise to the effect of external perturbation injection schemes. LA - English DB - MTMT ER - TY - JOUR AU - Nyáry, Anna AU - Balogh, Zoltán AU - Vigh, Máté AU - Sánta, Botond AU - Pósa, László AU - Halbritter, András Ernő TI - Voltage-time dilemma and stochastic threshold-voltage variation in pure-silver atomic switches JF - PHYSICAL REVIEW APPLIED J2 - PHYS REV APPL VL - 21 PY - 2024 IS - 1 SN - 2331-7019 DO - 10.1103/PhysRevApplied.21.014027 UR - https://m2.mtmt.hu/api/publication/34554374 ID - 34554374 AB - The formation and dissolution of silver nanowires plays a fundamental role in a broad range of resistive-switching devices, which fundamentally rely on the electrochemical-metallization phenomenon. It has been shown that resistive switching may also appear in pure metallic nanowires lacking any silver-ion-hosting embedding environment but this pure atomic switching mechanism differs fundamentally from the conventional electrochemical-metallization-based resistive switching. To facilitate the quantitative description of the former phenomenon, we investigate a broad range of Ag atomic junctions, with a special focus on the frequency dependence and the fundamentally stochastic cycle-to-cycle variation of the switching-threshold voltage. These devices are established in an ultrahigh-purity environment in which electrochemical metallization can be excluded. The measured characteristics are successfully described by a vibrational-pumping model, yielding consistent predictions for the weak frequency dependence and the large variance of the switching-threshold voltage. We also demonstrate that electrochemical-metallization-based resistive switching and pure atomic switching may appear in the same device structure and therefore the proper understanding of the pure atomic switching mechanism has a very relevant importance in silver-based electrochemical-metallization cells. © 2024 American Physical Society. LA - English DB - MTMT ER - TY - JOUR AU - Balogh, Zoltán AU - Mezei, Gréta AU - Tenk, N. AU - Magyarkuti, András AU - Halbritter, András Ernő TI - Configuration-Specific Insight into Single-Molecule Conductance and Noise Data Revealed by the Principal Component Projection Method JF - JOURNAL OF PHYSICAL CHEMISTRY LETTERS J2 - J PHYS CHEM LETT VL - 14 PY - 2023 IS - 22 SP - 5109 EP - 5118 PG - 10 SN - 1948-7185 DO - 10.1021/acs.jpclett.3c00677 UR - https://m2.mtmt.hu/api/publication/34040360 ID - 34040360 N1 - Funding Agency and Grant Number: Ministry of Culture and Innovation; National Research, Development and Innovation Office [TKP2021-NVA-02]; NKFI [K143169]; Bolyai Janos Research Scholarship of the Hungarian Academy of Sciences [UNKP-22-5]; New National Excellence Program of the Ministry of Culture and Innovation from the source of the National Research, Development, and Innovation Fund Funding text: The authors acknowledge useful discussion with Latha Venkataraman on the basics of noise analysis, and with Gemma C. Solomon, Joseph M. Hamill, William Bro-Jorgensen, and Kasper P. Lauritzen on machine-learning-based data analysis methods. This research was funded by the Ministry of Culture and Innovation and the National Research, Development and Innovation Office under Grant No. TKP2021-NVA-02 and the NKFI K143169 grant. Z.B. acknowledges the support of the Bolyai Janos Research Scholarship of the Hungarian Academy of Sciences and the UNKP-22-5 New National Excellence Program of the Ministry of Culture and Innovation from the source of the National Research, Development, and Innovation Fund. AB - We explore the merits of neural network boosted, principal-component-projection-based,unsupervised data classification in single-molecule break junctionmeasurements, demonstrating that this method identifies highly relevanttrace classes according to the well-defined and well-visualized internalcorrelations of the data set. To this end, we investigate single-moleculestructures exhibiting double molecular configurations, exploring therole of the leading principal components in the identification ofalternative junction evolution trajectories. We show how the properprincipal component projections can be applied to separately analyzethe high- or low-conductance molecular configurations, which we exploitin 1/f-type noise measurements on bipyridine molecules. This approachuntangles the unclear noise evolution of the entire data set, identifyingthe coupling of the aromatic ring to the electrodes through the pi orbitals in two distinct conductance regions, and its subsequent uncouplingas these configurations are stretched. LA - English DB - MTMT ER - TY - JOUR AU - Basa, Péter AU - Fodor, B. AU - Nagy, Zs. AU - Oyunbolor, B. AU - Hajtman, A. AU - Bordács, Sándor AU - Kézsmárki, István AU - Halbritter, András Ernő AU - Orbánová, Agnesa TI - Analysis of malaria infection byproducts with Mueller matrix transmission ellipsometry JF - THIN SOLID FILMS J2 - THIN SOLID FILMS VL - 766 PY - 2023 SN - 0040-6090 DO - 10.1016/j.tsf.2022.139637 UR - https://m2.mtmt.hu/api/publication/33548398 ID - 33548398 AB - In this work, hemozoin, a microcrystalline byproduct of the malaria parasites was studied by transmission Mueller matrix ellipsometry. Measurement data was collected for different magnetic field orientations and as a function of the density of the hemozoin suspension. Our ellipsometric study demonstrates the magnetic alignment of the hemozoin crystals via the corresponding large linear birefringence and dichroism signals. These results reveal optical anisotropies of this material, which could be utilized for future optimization of detection schemes or optical instruments for diagnostic use. LA - English DB - MTMT ER - TY - JOUR AU - Csontos, Miklós AU - Horst, Y. AU - Olalla, N.J. AU - Koch, U. AU - Shorubalko, I. AU - Halbritter, András Ernő AU - Leuthold, J. TI - Picosecond Time-Scale Resistive Switching Monitored in Real-Time JF - ADVANCED ELECTRONIC MATERIALS J2 - ADV ELECTRON MATER VL - 9 PY - 2023 IS - 6 SN - 2199-160X DO - 10.1002/aelm.202201104 UR - https://m2.mtmt.hu/api/publication/33831558 ID - 33831558 N1 - Funding Agency and Grant Number: Werner Siemens Stiftung; Swiss National Science Foundation under the Spark Project [196486]; NKFI [K128534] Funding text: This work was supported by the Werner Siemens Stiftung. M.C. acknowledges financial support from the Swiss National Science Foundation under the Spark Project Nr. 196486. A.H. acknowledges the NKFI K128534 grant. LA - English DB - MTMT ER - TY - JOUR AU - Pósa, László AU - Hornung, Péter AU - Török, Tímea Nóra AU - Schmid, Sebastian Werner AU - Arjmandabasi, Sadaf AU - Molnár, György AU - Baji, Zsófia AU - Dražić, Goran AU - Halbritter, András Ernő AU - Volk, János TI - Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO2 Phase Change Memory Devices JF - ACS APPLIED NANO MATERIALS J2 - ACS APPL NANO MATER VL - 6 PY - 2023 IS - 11 SP - 9137 EP - 9147 PG - 11 SN - 2574-0970 DO - 10.1021/acsanm.3c00150 UR - https://m2.mtmt.hu/api/publication/33879666 ID - 33879666 AB - Volatile memory devices relying on the Mott-type insulator-to-metaltransition of vanadium oxide (VO2) are widely utilizedin the field of neuromorphic computing. Such devices, however, arerealized in a nanoscale geometry, where the switching relies on theself-heating of an ultrasmall spot as well as the presence of extremelyhigh electric fields in the active region. In this paper, we investigatethe interplay of such nanoscale thermal and nonlinear electronic phenomenaby investigating the temperature and voltage dependent conductionproperties of our custom-designed VO2 devices, where aV-shaped electrode focuses the switching to an ultrasmall single-spotactive region. This simplified spatial structure of the active volumefacilitates the device modeling and the identification of physicalmechanisms behind the phase transition. We find that purely thermalor electronic effects fail to describe the device operation, however,according to our finite element simulations, a combined electronicand thermal model provides a precise description of the device characteristics.These results facilitate the understanding as well as the thermaland electronic design of novel VO2-based neuronal devices. LA - English DB - MTMT ER - TY - JOUR AU - Török, Tímea Nóra AU - Makk, Péter AU - Balogh, Zoltán AU - Csontos, Miklós AU - Halbritter, András Ernő TI - Quantum Transport Properties of Nanosized Ta2O5 Resistive Switches: Variable Transmission Atomic Synapses for Neuromorphic Electronics JF - ACS APPLIED NANO MATERIALS J2 - ACS APPL NANO MATER VL - 6 PY - 2023 IS - 22 SP - 21340 EP - 21349 PG - 10 SN - 2574-0970 DO - 10.1021/acsanm.3c04769 UR - https://m2.mtmt.hu/api/publication/34431981 ID - 34431981 LA - English DB - MTMT ER - TY - JOUR AU - Török, Tímea Nóra AU - Fehérvári, János Gergő AU - Mészáros, Gábor AU - Pósa, László AU - Halbritter, András Ernő TI - Tunable, Nucleation-Driven Stochasticity in Nanoscale Silicon Oxide Resistive Switching Memory Devices JF - ACS APPLIED NANO MATERIALS J2 - ACS APPL NANO MATER VL - 5 PY - 2022 IS - 5 SP - 6691 EP - 6698 PG - 8 SN - 2574-0970 DO - 10.1021/acsanm.2c00722 UR - https://m2.mtmt.hu/api/publication/32821968 ID - 32821968 AB - Resistive switching memory devices hold extensive possibilities for realizing artificial neural networks along with nonconventional computing paradigms. Studying and understanding phenomena arising at single resistive switching elements is necessary for utilizing their particular traits for computation. Tuning the variability of the set time the timespan before the onset of the transition from a high-resistance OFF state to a low-resistance ON state is key for making use of the inherently stochastic nature of the resistance switching effect. Here, we study the set time statistics in nanometer-sized graphene-SiOx-graphene resistive switching memory devices. For dedicated OFF state configurations, we demonstrate a universal variance of the logarithmic set time values, which is characteristic to a nucleation-driven crystallization process. Furthermore, we observe clear correlation between the OFF state resistance and the set time, and hence we explore the tunability of the set time statistics via changing the reset amplitude parameter in sequential pulsed measurements. The latter phenomenon could prove useful for controlling stochasticity in memristor-based probabilistic computing applications via the control of the active volume's nanostructure. © 2022 The Authors. Published by American Chemical Society. LA - English DB - MTMT ER - TY - JOUR AU - Balogh, Zoltán AU - Mezei, Gréta AU - Pósa, László AU - Sánta, Botond AU - Magyarkuti, András AU - Halbritter, András Ernő TI - 1/f noise spectroscopy and noise tailoring of nanoelectronic devices JF - NANO FUTURES J2 - NANO FUTURES VL - 5 PY - 2021 IS - 4 PG - 11 SN - 2399-1984 DO - 10.1088/2399-1984/ac14c8 UR - https://m2.mtmt.hu/api/publication/32183347 ID - 32183347 LA - English DB - MTMT ER - TY - GEN AU - Botond, Sánta AU - Zoltán, Balogh AU - Pósa, László AU - Tímea, Nóra Török AU - Dániel, Molnár AU - Miklós, Csontos AU - Halbritter, András Ernő TI - Noise Tailoring in Memristive Filaments CY - Tsukuba, Japán, 2021.11.01-2021.11.04. PY - 2021 UR - https://m2.mtmt.hu/api/publication/32800966 ID - 32800966 AB - We present the possibilities of noise tailoring in filamentary resistive switching memory devices. The resistance and frequency scaling of the low-frequency 1/f-type noise properties are studied in representative mainstream material systems. It is shown that the overall noise floor is tailorable by the proper material choice, as demonstrated by the order-of-magnitude smaller noise levels in Ta2O5 and Nb2O5 transition-metal oxide memristors compared to Ag-based devices. Furthermore, the variation of the resistance states allows orders-of-magnitude tuning of the relative noise level in all of these material systems. This behavior is analyzed in the framework of a point-contact noise model highlighting the possibility for the disorder-induced suppression of the noise contribution arising from remote fluctuators. These findings promote the design of multipurpose resistive switching units, which can simultaneously serve as analog-tunable memory elements and tunable noise sources in probabilistic computing machines. LA - English DB - MTMT ER - TY - JOUR AU - Magyarkuti, András AU - Balogh, Zoltán AU - Mezei, Gréta AU - Halbritter, András Ernő TI - Structural Memory Effects in Gold–4,4′-Bipyridine–Gold Single-Molecule Nanowires JF - JOURNAL OF PHYSICAL CHEMISTRY LETTERS J2 - J PHYS CHEM LETT VL - 12 PY - 2021 SP - 1759 EP - 1764 PG - 6 SN - 1948-7185 DO - 10.1021/acs.jpclett.0c03765 UR - https://m2.mtmt.hu/api/publication/31868928 ID - 31868928 N1 - Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, Budapest, 1111, Hungary MTA-BME Condensed Matter Research Group, Budafoki ut 8, Budapest, 1111, Hungary Export Date: 11 May 2021 Correspondence Address: Balogh, Z.; Department of Physics, Budafoki ut 8, Hungary; email: balogh.zoltan@mail.bme.hu Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, Budapest, 1111, Hungary MTA-BME Condensed Matter Research Group, Budafoki ut 8, Budapest, 1111, Hungary Export Date: 31 May 2021 Correspondence Address: Balogh, Z.; Department of Physics, Budafoki ut 8, Hungary; email: balogh.zoltan@mail.bme.hu Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, Budapest, 1111, Hungary MTA-BME Condensed Matter Research Group, Budafoki ut 8, Budapest, 1111, Hungary Export Date: 15 September 2021 Correspondence Address: Balogh, Z.; Department of Physics, Budafoki ut 8, Hungary; email: balogh.zoltan@mail.bme.hu Funding Agency and Grant Number: NKFINational Research, Development & Innovation Office (NRDIO) - Hungary [K119797]; NRDI Fund of the Ministry for Innovation and TechnologyNational Research, Development & Innovation Office (NRDIO) - Hungary [BME-IE-NAT] Funding text: The research reported in this paper was supported by the NKFI K119797 grant and the NRDI Fund (TKP2020 IES, Grant No. BME-IE-NAT) based on the charter of bolster issued by the NRDI Office under the auspices of the Ministry for Innovation and Technology. The authors are thankful to K. P. Lauritzen and G. C. Solomon for the graphical illustration of the gold-BP-gold structures. LA - English DB - MTMT ER - TY - JOUR AU - Pósa, László AU - Balogh, Zoltán AU - Krisztián, Dávid AU - Balázs, Péter AU - Sánta, Botond AU - Furrer, Roman AU - Csontos, Miklós AU - Halbritter, András Ernő TI - Noise diagnostics of graphene interconnects for atomic-scale electronics JF - NPJ 2D MATERIALS AND APPLICATIONS J2 - NPJ 2D MATER APPL VL - 5 PY - 2021 IS - 1 PG - 9 SN - 2397-7132 DO - 10.1038/s41699-021-00237-w UR - https://m2.mtmt.hu/api/publication/32040083 ID - 32040083 AB - Graphene nanogaps are considered as essential building blocks of two-dimensional electronic circuits, as they offer the possibility to interconnect a broad range of atomic-scale objects. Here we provide an insight into the microscopic processes taking place during the formation of graphene nanogaps through the detailed analysis of their low-frequency noise properties. Following the evolution of the noise level, we identify the fundamentally different regimes throughout the nanogap formation. By modeling the resistance and bias dependence of the noise, we resolve the major noise-generating processes: atomic-scale junction-width fluctuations in the nanojunction regime and sub-atomic gap-size fluctuations in the nanogap regime. As a milestone toward graphene-based atomic electronics, our results facilitate the automation of an optimized electrical breakdown protocol for high-yield graphene nanogap fabrication. LA - English DB - MTMT ER - TY - JOUR AU - Sánta, Botond AU - Balogh, Zoltán AU - Pósa, László AU - Krisztián, Dávid AU - Török, Tímea Nóra AU - Molnár, Dániel AU - Sinkó, Csaba AU - Hauert, Roland AU - Csontos, Miklós AU - Halbritter, András Ernő TI - Noise Tailoring in Memristive Filaments JF - ACS APPLIED MATERIALS & INTERFACES J2 - ACS APPL MATER INTER VL - 13 PY - 2021 IS - 6 SP - 7453 EP - 7460 PG - 8 SN - 1944-8244 DO - 10.1021/acsami.0c21156 UR - https://m2.mtmt.hu/api/publication/31867344 ID - 31867344 LA - English DB - MTMT ER - TY - JOUR AU - Magyarkuti, András AU - Balogh, Nóra AU - Balogh, Zoltán AU - Venkataraman, Latha AU - Halbritter, András Ernő TI - Unsupervised feature recognition in single-molecule break junction data JF - NANOSCALE J2 - NANOSCALE VL - 12 PY - 2020 IS - 15 SP - 8355 EP - 8363 PG - 9 SN - 2040-3364 DO - 10.1039/D0NR00467G UR - https://m2.mtmt.hu/api/publication/31265427 ID - 31265427 N1 - Funding Agency and Grant Number: BME-Nanonotechnology FIKP grant of EMMI (BME FIKP-NAT); NKFI [K119797]; NSF-DMRNational Science Foundation (NSF) [1807580] Funding text: This work was supported by the BME-Nanonotechnology FIKP grant of EMMI (BME FIKP-NAT) and the NKFI K119797 grant. L. V. thanks the NSF-DMR 1807580 grant for support. The authors are thankful to Kasper P. Lauritzen and Gemma C. Solomon for useful discussions and for inspiration to this work, and to Sriharsha V. Aradhya and Michael Frei for the room temperature force measurement data. Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, Budapest, 1111, Hungary MTA-BME Condensed Matter Research Group, Budafoki ut 8, Budapest, 1111, Hungary Department of Applied Physics, Columbia University, New York, NY 10027, United States Department of Chemistry, Columbia University, New York, NY 10027, United States LA - English DB - MTMT ER - TY - JOUR AU - Mezei, Gréta AU - Balogh, Zoltán AU - Magyarkuti, András AU - Halbritter, András Ernő TI - Voltage-Controlled Binary Conductance Switching in Gold-4,4 '-Bipyridine-Gold Single-Molecule Nanowires JF - JOURNAL OF PHYSICAL CHEMISTRY LETTERS J2 - J PHYS CHEM LETT VL - 11 PY - 2020 IS - 19 SP - 8053 EP - 8059 PG - 7 SN - 1948-7185 DO - 10.1021/acs.jpclett.0c02185 UR - https://m2.mtmt.hu/api/publication/31694496 ID - 31694496 N1 - https://arxiv.org/abs/2006.04460 Department of Physics, Budapest University of Technology and Economics, Budapest, 1111, Hungary Mtabme Condensed Matter Research Group, Budapest, 1111, Hungary Export Date: 12 January 2021 Correspondence Address: Halbritter, A.; Department of Physics, Budapest University of Technology and EconomicsHungary; email: halbritt@mail.bme.hu Department of Physics, Budapest University of Technology and Economics, Budapest, 1111, Hungary Mtabme Condensed Matter Research Group, Budapest, 1111, Hungary Export Date: 13 January 2021 Correspondence Address: Halbritter, A.; Department of Physics, Budapest University of Technology and EconomicsHungary; email: halbritt@mail.bme.hu Department of Physics, Budapest University of Technology and Economics, Budapest, 1111, Hungary Mtabme Condensed Matter Research Group, Budapest, 1111, Hungary AB - We investigate gold-4,4'-bipyridine-gold single-molecule junctions with the mechanically controllable break junction technique at cryogenic temperature (T = 4.2 K). We observe bistable probabilistic conductance switching between the two molecular binding configurations, influenced both by the mechanical actuation and by the applied voltage. We demonstrate that the relative dominance of the two conductance states is tunable by the electrode displacement, whereas the voltage manipulation induces an exponential speedup of both switching times. The detailed investigation of the voltage-tunable switching rates provides an insight into the possible switching mechanisms. LA - English DB - MTMT ER - TY - JOUR AU - Nyáry, Anna AU - Gubicza, Ágnes AU - Overbeck, Jan AU - Pósa, László AU - Makk, Péter AU - Calame, Michel AU - Halbritter, András Ernő AU - Csontos, Miklós TI - A non-oxidizing fabrication method for lithographic break junctions of sensitive metals JF - NANOSCALE ADVANCES J2 - NANOSCALE ADV VL - 2 PY - 2020 IS - 9 SP - 3829 EP - 3833 PG - 5 SN - 2516-0230 DO - 10.1039/D0NA00498G UR - https://m2.mtmt.hu/api/publication/31592175 ID - 31592175 LA - English DB - MTMT ER - TY - JOUR AU - Sánta, Botond AU - Molnár, Dániel AU - Haiber, P AU - Gubicza, A AU - Szilágyi, Edit AU - Zolnai, Zsolt AU - Halbritter, András Ernő AU - Csontos, Miklós TI - Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions JF - BEILSTEIN JOURNAL OF NANOTECHNOLOGY J2 - BEILSTEIN J NANOTECH VL - 11 PY - 2020 SP - 92 EP - 100 PG - 9 SN - 2190-4286 DO - 10.3762/bjnano.11.9 UR - https://m2.mtmt.hu/api/publication/31043925 ID - 31043925 AB - Nanometer-scale resistive switching devices operated in the metallic conductance regime offer ultimately scalable and widely reconfigurable hardware elements for novel in-memory and neuromorphic computing architectures. Moreover, they exhibit high operation speed at low power arising from the ease of the electric-field-driven redistribution of only a small amount of highly mobile ionic species upon resistive switching. We investigate the memristive behavior of a so-far less explored representative of this class, the Ag/AgI material system in a point contact arrangement established by the conducting PtIr tip of a scanning probe microscope. We demonstrate stable resistive switching duty cycles and investigate the dynamical aspects of non-volatile operation in detail. The high-speed switching capabilities are explored by a custom-designed microwave setup that enables time-resolved studies of subsequent set and reset transitions upon biasing the Ag/AgI/PtIr nanojunctions with sub-nanosecond voltage pulses. Our results demonstrate the potential of Ag-based filamentary memristive nanodevices to serve as the hardware elements in high-speed neuromorphic circuits. LA - English DB - MTMT ER - TY - JOUR AU - Török, Tímea Nóra AU - Csontos, Miklós AU - Makk, Péter AU - Halbritter, András Ernő TI - Breaking the Quantum PIN Code of Atomic Synapses JF - NANO LETTERS J2 - NANO LETT VL - 20 PY - 2020 IS - 2 SP - 1192 EP - 1200 PG - 9 SN - 1530-6984 DO - 10.1021/acs.nanolett.9b04617 UR - https://m2.mtmt.hu/api/publication/31126336 ID - 31126336 LA - English DB - MTMT ER - TY - GEN AU - B., Sánta AU - Z., Balogh AU - A., Gubicza AU - Pósa, László AU - D., Krisztián AU - G., Mihály AU - M., Csontos AU - Halbritter, András Ernő TI - Universal 1/f type current noise of Ag filaments in redox-based memristive nanojunctions CY - Drezda, Németország, 2019.07.08.-2019.07.11. PY - 2019 UR - https://m2.mtmt.hu/api/publication/32800980 ID - 32800980 AB - The microscopic origins and technological impact of 1/f type current fluctuations in Ag based, filamentary type resistive switching devices have been investigated upon downscaling toward the ultimate single atomic limit. The analysis of the low-frequency current noise spectra revealed that the main electronic noise contribution arises from the resistance fluctuations due to internal dynamical defects of Ag nanofilaments. The resulting 0.01–1% current noise ratio, i.e. the total noise level with respect to the mean value of the current, is found to be universal: its magnitude only depends on the total resistance of the device, irrespective of the materials aspects of the surrounding solid electrolyte and of the specific filament formation procedure. Moreover, the resistance dependence of the current noise ratio also displays the diffusive to ballistic crossover, confirming that stable resistive switching operation utilizing Ag nanofilaments is not compromised even in truly atomic scale junctions by technologically impeding noise levels. LA - English DB - MTMT ER - TY - JOUR AU - Sánta, Botond AU - Balogh, Zoltán AU - Gubicza, Ágnes AU - Pósa, László AU - Krisztián, Dávid AU - Mihály, György AU - Csontos, Miklós AU - Halbritter, András Ernő TI - Universal 1/f type current noise of Ag filaments in redox-based memristive nanojunctions JF - NANOSCALE J2 - NANOSCALE VL - 11 PY - 2019 IS - 11 SP - 4719 EP - 4725 PG - 7 SN - 2040-3364 DO - 10.1039/c8nr09985e UR - https://m2.mtmt.hu/api/publication/30538957 ID - 30538957 LA - English DB - MTMT ER -