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 - 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 - 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 - 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 - Lauritzen, KP AU - Magyarkuti, András AU - Balogh, Zoltán AU - Halbritter, András Ernő AU - Solomon, GC TI - Classification of conductance traces with recurrent neural networks JF - JOURNAL OF CHEMICAL PHYSICS J2 - J CHEM PHYS VL - 148 PY - 2018 IS - 8 PG - 10 SN - 0021-9606 DO - 10.1063/1.5012514 UR - https://m2.mtmt.hu/api/publication/3346970 ID - 3346970 AB - We present a new automated method for structural classification of the traces obtained in break junction experiments. Using recurrent neural networks trained on the traces of minimal cross-sectional area in molecular dynamics simulations, we successfully separate the traces into two classes: point contact or nanowire. This is done without any assumptions about the expected features of each class. The trained neural network is applied to experimental break junction conductance traces, and it separates the classes as well as the previously used experimental methods. The effect of using partial conductance traces is explored, and we show that the method performs equally well using full or partial traces (as long as the trace just prior to breaking is included). When only the initial part of the trace is included, the results are still better than random chance. Finally, we show that the neural network classification method can be used to classify experimental conductance traces without using simulated results for training, but instead training the network on a few representative experimental traces. This offers a tool to recognize some characteristic motifs of the traces, which can be hard to find by simple data selection algorithms. LA - English DB - MTMT ER - TY - JOUR AU - Magyarkuti, András AU - Adak, Olgun AU - Halbritter, András Ernő AU - Venkataraman, Latha TI - Electronic and Mechanical Characteristics of Stacked Dimer Molecular Junctions JF - NANOSCALE J2 - NANOSCALE VL - 10 PY - 2018 IS - 7 SP - 3362 EP - 3368 PG - 7 SN - 2040-3364 DO - 10.1039/C7NR08354H UR - https://m2.mtmt.hu/api/publication/3322772 ID - 3322772 AB - Break-junction measurements are typically aimed at characterizing electronic properties of single molecules bound between two metal electrodes. Although these measurements have provided structure-function relations for such devices, there is little work that studies the impact of molecule-molecule interaction on junction characteristics. Here, we use scanning tunneling microscope based break-junction technique to study pi-stacked dimer junctions formed with two amine-terminated conjugated molecules. We show that the conductance, force and flicker noise of such dimers differ dramatically when compared with the corresponding monomer junctions and discuss the implications of these results on intra and inter-molecular charge transport. LA - English DB - MTMT ER - TY - JOUR AU - Molnár, Dániel AU - Török, Tímea Nóra AU - Sánta, Botond AU - Gubicza, Ágnes AU - Magyarkuti, András AU - Hauert, Roland AU - Kiss, Gábor AU - Halbritter, András Ernő AU - Csontos, Miklós TI - In situ impedance matching in Nb/Nb 2 O 5 /PtIr memristive nanojunctions for ultra-fast neuromorphic operation JF - NANOSCALE J2 - NANOSCALE VL - 10 PY - 2018 IS - 41 SP - 19290 EP - 19296 PG - 7 SN - 2040-3364 DO - 10.1039/C8NR06226A UR - https://m2.mtmt.hu/api/publication/30369444 ID - 30369444 LA - English DB - MTMT ER - TY - JOUR AU - Magyarkuti, András AU - K P, Lauritzen AU - Balogh, Zoltán AU - Nyáry, Anna AU - Mészáros, Gábor AU - Makk, Péter AU - G C, Solomon AU - Halbritter, András Ernő TI - Temporal correlations and structural memory effects in break junction measurements JF - JOURNAL OF CHEMICAL PHYSICS J2 - J CHEM PHYS VL - 146 PY - 2017 IS - 9 SN - 0021-9606 DO - 10.1063/1.4975180 UR - https://m2.mtmt.hu/api/publication/3184494 ID - 3184494 LA - English DB - MTMT ER - TY - JOUR AU - Sánta, Botond AU - Magyarkuti, András AU - Halbritter, András Ernő TI - Egy demonstrációs kísérlet, amelyben az áram egyetlen atomon keresztül folyik JF - FIZIKAI SZEMLE J2 - FIZIKAI SZEMLE VL - 66 PY - 2016 IS - 5 SP - 154 EP - 160 PG - 7 SN - 0015-3257 UR - https://m2.mtmt.hu/api/publication/3084482 ID - 3084482 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Lazányi, Nóra AU - Horváth, László AU - Magyarkuti, András AU - Papp, Gergely AU - Pokol, Gergő AU - Pór, Gábor AU - Valentin, Igochine AU - Marc, Maraschek ED - ASDEX, Upgrade Team / Collaborative Organization TI - Alacsony frekvenciás fűrészfog prekurzor vizsgálata az ASDEX Upgrade tokamakon JF - NUKLEON J2 - NUKLEON VL - 5 PY - 2012 PG - 5 SN - 1789-9613 UR - https://m2.mtmt.hu/api/publication/2697369 ID - 2697369 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Papp, Gergely AU - Pokol, Gergő AU - Pór, Gábor AU - Magyarkuti, András AU - Lazányi, Nóra AU - Horvath, L AU - Igochine, V AU - Maraschek, M TI - Low frequency sawtooth precursor activity in ASDEX Upgrade JF - PLASMA PHYSICS AND CONTROLLED FUSION J2 - PLASMA PHYS CONTR F VL - 53 PY - 2011 IS - 6 PG - 17 SN - 0741-3335 DO - 10.1088/0741-3335/53/6/065007 UR - https://m2.mtmt.hu/api/publication/1886811 ID - 1886811 N1 - Megjegyzés-21621005 CA: ASDEZ Upgrade Team Megjegyzés-22448240 CA ASDEZ Upgrade Team Megjegyzés-22985381 CA ASDEZ Upgrade Team Megjegyzés-23622077 CA ASDEZ Upgrade Team : Gabor/H-6806-2012; Lazanyi, Nora/I-6310-2012; Papp, Gergely/J-6106-2012 Megjegyzés-23623304 CA ASDEZ Upgrade Team : Gabor/H-6806-2012; Lazanyi, Nora/I-6310-2012; Papp, Gergely/J-6106-2012 Megjegyzés-23623446 CA ASDEZ Upgrade Team : Gabor/H-6806-2012; Lazanyi, Nora/I-6310-2012; Papp, Gergely/J-6106-2012 Megjegyzés-23623499 CA ASDEZ Upgrade Team : Gabor/H-6806-2012; Lazanyi, Nora/I-6310-2012; Papp, Gergely/J-6106-2012 Megjegyzés-25331961 CA ASDEZ Upgrade Team Megjegyzés-25341868 CA ASDEZ Upgrade Team Megjegyzés-25371477 CA ASDEZ Upgrade Team Megjegyzés-25376881 CA ASDEZ Upgrade Team Megjegyzés-25377521 CA ASDEZ Upgrade Team Megjegyzés-25377798 CA ASDEZ Upgrade Team Megjegyzés-25666008 CA ASDEZ Upgrade Team Megjegyzés-25714858 CA ASDEZ Upgrade Team AB - This paper describes the precursor activity observed in the ASDEX Upgrade tokamak before sawtooth crashes in various neutral beam heated plasmas, utilizing the soft x-ray diagnostic. In addition to the well-known (m, n) = (1,1) internal kink mode and its harmonics, a lower frequency mode is studied in detail. Power modulation of this mode is found to correlate with the power modulation of the (1, 1) kink mode in the quasistationary intervals indicating possible nonlinear interaction. Throughout the studied sawtooth crashes, the power of the lower frequency mode rose by several orders of magnitude just before the crash. In addition to its temporal behaviour, its spatial structure was estimated and the most likely value was found to be (1, 1). A possible role of this mode in the mechanism of the sawtooth crash is discussed. LA - English DB - MTMT ER -