People
Research Fellow
Sergey Grebenchuk
Title
Research Fellow
Research Interests
Magnetism, superconductivity, van der Waals materials, neuromorphic devices
Research Group
Office Location
S9-09-01-41
Selected Publications
- Grebenchuk, S., McKeever, C., Grzeszczyk, M., Chen, Z., Šiškins, M., McCray, A. R. C., Li, Y., Petford-Long, A. K., Phatak, C. M., Ruihuan, D., Zheng, L., Novoselov, K. S., Santos, E. J. G., Koperski, M. “Topological spin textures in an insulating van der Waals ferromagnet.” Advanced Materials, 36, 2311949, 2024
- Dremov, V.V., Grebenchuk, S.Y., Shishkin, A.G., Baranov, D.S., Hovhannisyan, R.A., Skryabina, O.V., Lebedev, N., Golovchanskiy, I.A., Chichkov, V.I., Brun, C., Cren, T., Krasnov, V.M., Golubov A.G., Roditchev, D., Stolyarov, V.S., Local Josephson vortex generation and manipulation with a Magnetic Force Microscope. Nature communications, 10(1), pp.1-9, 2019
I-FIM Publications:
2026 |
Zhang, Hongji; Grebenko, Artem K; Litvinov, Dmitrii; Zheng, Wenwen; Iakoubovskii, Konstantin V; Grebenchuk, Sergey Y; Makarova, Anna; Fedorov, Alexander; Starkov, Andrei; Orofeo, Carlo M; Vyalikh, Denis V; Lanza, Mario; Koperski, Maciej; Novoselov, Kostya S; Toh, Chee-tat; Ozyilmaz, Barbaros Breaking the 2-nm Barrier in Hard Disk Drives Using Monolayer Amorphous Carbon Overcoats ADVANCED MATERIALS, 38 (15), 2026, DOI: 10.1002/adma.202519149. @article{WOS:001680918000001, title = {Breaking the 2-nm Barrier in Hard Disk Drives Using Monolayer Amorphous Carbon Overcoats}, author = {Hongji Zhang and Artem K Grebenko and Dmitrii Litvinov and Wenwen Zheng and Konstantin V Iakoubovskii and Sergey Y Grebenchuk and Anna Makarova and Alexander Fedorov and Andrei Starkov and Carlo M Orofeo and Denis V Vyalikh and Mario Lanza and Maciej Koperski and Kostya S Novoselov and Chee-tat Toh and Barbaros Ozyilmaz}, doi = {10.1002/adma.202519149}, times_cited = {0}, issn = {0935-9648}, year = {2026}, date = {2026-03-01}, journal = {ADVANCED MATERIALS}, volume = {38}, number = {15}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {The rapid growth of artificial intelligence (AI) has increased the demand for large-scale data storage, making hard disk drives (HDDs) indispensable in data centers due to their cost-effectiveness and stability. To support AI-driven data requirements, increasing the areal storage density is critical. However, this metric is increasingly constrained by the carbon overcoat (COC), the essential protective layer for magnetic media. Traditional diamond-like carbon (DLC) can no longer fulfill the stringent demands for ultrathin coatings and high thermal stability required by next-generation technologies like Heat-Assisted Magnetic Recording (HAMR) and bit-patterned media. Here, we introduce monolayer amorphous carbon (MAC) as a superior alternative. MAC is directly grown on the heterogeneous (Fe, Pt, SiO2) HDD surface at low temperatures (similar to 300 degrees C), achieving an uniform 0.8 nm thickness across 2.5-inch disks. Despite its atomic thickness, MAC demonstrates high corrosion resistance and low roughness comparable to commercial 2.5 nm COCs. Its fully amorphous, sp2-hybridized structure ensures excellent thermal stability under HAMR-like conditions (similar to 450 degrees C) and a low friction coefficient, enabling potential lubricant-free operation. Replacing traditional COCs with MAC facilitates the development of HDD media capable of achieving 10 Tb/in2, addressing the urgent storage demands of the digital era.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The rapid growth of artificial intelligence (AI) has increased the demand for large-scale data storage, making hard disk drives (HDDs) indispensable in data centers due to their cost-effectiveness and stability. To support AI-driven data requirements, increasing the areal storage density is critical. However, this metric is increasingly constrained by the carbon overcoat (COC), the essential protective layer for magnetic media. Traditional diamond-like carbon (DLC) can no longer fulfill the stringent demands for ultrathin coatings and high thermal stability required by next-generation technologies like Heat-Assisted Magnetic Recording (HAMR) and bit-patterned media. Here, we introduce monolayer amorphous carbon (MAC) as a superior alternative. MAC is directly grown on the heterogeneous (Fe, Pt, SiO2) HDD surface at low temperatures (similar to 300 degrees C), achieving an uniform 0.8 nm thickness across 2.5-inch disks. Despite its atomic thickness, MAC demonstrates high corrosion resistance and low roughness comparable to commercial 2.5 nm COCs. Its fully amorphous, sp2-hybridized structure ensures excellent thermal stability under HAMR-like conditions (similar to 450 degrees C) and a low friction coefficient, enabling potential lubricant-free operation. Replacing traditional COCs with MAC facilitates the development of HDD media capable of achieving 10 Tb/in2, addressing the urgent storage demands of the digital era.
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Jana, Dipankar; Mukherjee, Shubhrasish; Litvinov, Dmitrii; Grzeszczyk, Magdalena; Grebenchuk, Sergey; Siskins, Makars; Gavriliuc, Virgil; Ouyang, Yihang; Chen, Changyi; Ye, Yuxuan; Yiming, Meng; Koperski, Maciej Two-Dimensional Materials as a Multiproperty Sensing Platform ADVANCED FUNCTIONAL MATERIALS, 36 (14), 2026, DOI: 10.1002/adfm.202516728. @article{WOS:001619984500001, title = {Two-Dimensional Materials as a Multiproperty Sensing Platform}, author = {Dipankar Jana and Shubhrasish Mukherjee and Dmitrii Litvinov and Magdalena Grzeszczyk and Sergey Grebenchuk and Makars Siskins and Virgil Gavriliuc and Yihang Ouyang and Changyi Chen and Yuxuan Ye and Meng Yiming and Maciej Koperski}, doi = {10.1002/adfm.202516728}, times_cited = {3}, issn = {1616-301X}, year = {2026}, date = {2026-02-01}, journal = {ADVANCED FUNCTIONAL MATERIALS}, volume = {36}, number = {14}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {Two-dimensional (2D) materials have disrupted materials science due to the development of van der Waals technology. It enables the stacking of ultrathin layers of materials characterized by vastly different electronic structures to create man-made heterostructures and devices with rationally tailored properties, circumventing limitations of matching crystal structures, lattice constants, and geometry of constituent materials and supporting substrates. 2D materials exhibit extraordinary mechanical flexibility, strong light-matter interactions driven by their excitonic response, single photon emission from atomic centers, stable ferromagnetism in sub-nm thin films, fractional quantum Hall effect in high-quality devices, and chemoselectivity at ultrahigh surface-to-volume ratio. Consequently, van der Waals heterostructures with atomically flat interfaces demonstrate an unprecedented degree of intertwined mechanical, chemical, optoelectronic, and magnetic properties. This constitutes a foundation for multiproperty sensing, based on complex intra- and intermaterial interactions, and a robust response to external stimuli originating from the environment. Here, recent progress are reviewed in the development of sensing applications with 2D materials, highlighting the areas where van der Waals heterostructures offer the highest sensitivity, simultaneous responses to multiple distinct externalities due to their atomic thickness in conjunction with unique material combinations, and conceptually new sensing methodology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two-dimensional (2D) materials have disrupted materials science due to the development of van der Waals technology. It enables the stacking of ultrathin layers of materials characterized by vastly different electronic structures to create man-made heterostructures and devices with rationally tailored properties, circumventing limitations of matching crystal structures, lattice constants, and geometry of constituent materials and supporting substrates. 2D materials exhibit extraordinary mechanical flexibility, strong light-matter interactions driven by their excitonic response, single photon emission from atomic centers, stable ferromagnetism in sub-nm thin films, fractional quantum Hall effect in high-quality devices, and chemoselectivity at ultrahigh surface-to-volume ratio. Consequently, van der Waals heterostructures with atomically flat interfaces demonstrate an unprecedented degree of intertwined mechanical, chemical, optoelectronic, and magnetic properties. This constitutes a foundation for multiproperty sensing, based on complex intra- and intermaterial interactions, and a robust response to external stimuli originating from the environment. Here, recent progress are reviewed in the development of sensing applications with 2D materials, highlighting the areas where van der Waals heterostructures offer the highest sensitivity, simultaneous responses to multiple distinct externalities due to their atomic thickness in conjunction with unique material combinations, and conceptually new sensing methodology.
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Fullerton, John; Li, Yue; Solanki, Harshvardhan; Grebenchuk, Sergey; Grzeszczyk, Magdalena; Chen, Zhaolong; Siskins, Makars; Novoselov, Kostya S; Koperski, Maciej; Santos, Elton J G; Phatak, Charudatta Observation of Topological Chirality Switching Induced Freezing of a Skyrmion Crystal ADVANCED MATERIALS, 38 (9), 2026, DOI: 10.1002/adma.202513067. @article{WOS:001601237600001, title = {Observation of Topological Chirality Switching Induced Freezing of a Skyrmion Crystal}, author = {John Fullerton and Yue Li and Harshvardhan Solanki and Sergey Grebenchuk and Magdalena Grzeszczyk and Zhaolong Chen and Makars Siskins and Kostya S Novoselov and Maciej Koperski and Elton J G Santos and Charudatta Phatak}, doi = {10.1002/adma.202513067}, times_cited = {2}, issn = {0935-9648}, year = {2026}, date = {2026-02-01}, journal = {ADVANCED MATERIALS}, volume = {38}, number = {9}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {Magnetic skyrmions are topologically protected quasi-particles with a well-defined chirality. Control over their chirality is proposed as an additional feature for encoding data bits or as qubits in quantum computing due to their high efficiency and stability against achiral magnetic textures. Here it is shown that an in-plane magnetic field can be utilized to reshape the energy barriers between different skyrmionic bubbles (e.g., Bloch type, type-II) enabling spontaneous chirality fluctuations with a frequency that increases with the strength of the in-plane field. The insulating van der Waals ferromagnet CrBr3 is used as an archetypal system for low damping, reduced energy dissipation and a high number of magnetic phases to capture the chirality dynamics in real time through cryo-Lorentz transmission electron microscopy. It is observed that the interplay between the intrinsic Dzyaloshinskii-Moriya interaction and out-of-plane field biased the chirality dynamics, favoring one handedness over the other. A remarkable consequence of the spontaneous chirality switching mechanism is that it induces a freezing (or crystallization) process in the skyrmion lattice. As the bubbles fluctuate between Bloch and type-II they elongate and shrink parallel to the in-plane field. Subsequently, the overall lattice crystallizes along the in-plane field direction, inducing a phase transition from a disordered liquid state to a hexatic phase where skyrmions are highly ordered resembling that of a solid. The results indicate chirality as an active element in the creation of topologically protected skyrmion crystals unveiling pathways toward chiral spintronic device platforms with tunable embedded configuration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Magnetic skyrmions are topologically protected quasi-particles with a well-defined chirality. Control over their chirality is proposed as an additional feature for encoding data bits or as qubits in quantum computing due to their high efficiency and stability against achiral magnetic textures. Here it is shown that an in-plane magnetic field can be utilized to reshape the energy barriers between different skyrmionic bubbles (e.g., Bloch type, type-II) enabling spontaneous chirality fluctuations with a frequency that increases with the strength of the in-plane field. The insulating van der Waals ferromagnet CrBr3 is used as an archetypal system for low damping, reduced energy dissipation and a high number of magnetic phases to capture the chirality dynamics in real time through cryo-Lorentz transmission electron microscopy. It is observed that the interplay between the intrinsic Dzyaloshinskii-Moriya interaction and out-of-plane field biased the chirality dynamics, favoring one handedness over the other. A remarkable consequence of the spontaneous chirality switching mechanism is that it induces a freezing (or crystallization) process in the skyrmion lattice. As the bubbles fluctuate between Bloch and type-II they elongate and shrink parallel to the in-plane field. Subsequently, the overall lattice crystallizes along the in-plane field direction, inducing a phase transition from a disordered liquid state to a hexatic phase where skyrmions are highly ordered resembling that of a solid. The results indicate chirality as an active element in the creation of topologically protected skyrmion crystals unveiling pathways toward chiral spintronic device platforms with tunable embedded configuration.
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2025 |
Fu, Deyi; Liu, Jiawei; Hou, Fuchen; Chang, Xiao; Qu, Tingyu; Felisaz, Johan; Krishnaswamy, Gunasheel Kauwtilyaa; Grebenchuk, Sergey; Jie, Yuang; Watanabe, Kenji; Taniguchi, Takashi; Pereira, Vitor M; Novoselov, Kostya S; Koperski, Maciej; Yakovlev, Nikolai L; Soumyanarayanan, Anjan; Avsar, Ahmet; Yazyev, Oleg V; Lin, Junhao; Ozyilmaz, Barbaros Electric field-tunable ferromagnetism in a van der Waals semiconductor up to room temperature NATURE COMMUNICATIONS, 16 (1), 2025, DOI: 10.1038/s41467-025-59961-2. @article{WOS:001620530800035, title = {Electric field-tunable ferromagnetism in a van der Waals semiconductor up to room temperature}, author = {Deyi Fu and Jiawei Liu and Fuchen Hou and Xiao Chang and Tingyu Qu and Johan Felisaz and Gunasheel Kauwtilyaa Krishnaswamy and Sergey Grebenchuk and Yuang Jie and Kenji Watanabe and Takashi Taniguchi and Vitor M Pereira and Kostya S Novoselov and Maciej Koperski and Nikolai L Yakovlev and Anjan Soumyanarayanan and Ahmet Avsar and Oleg V Yazyev and Junhao Lin and Barbaros Ozyilmaz}, doi = {10.1038/s41467-025-59961-2}, times_cited = {1}, year = {2025}, date = {2025-11-01}, journal = {NATURE COMMUNICATIONS}, volume = {16}, number = {1}, publisher = {NATURE PORTFOLIO}, address = {HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY}, abstract = {Ferromagnetic semiconductors, coupling charge transport and magnetism via electrical means, show great promise for spin-based logic devices. Despite decades of efforts to achieve such co-functionality, maintaining ferromagnetic order at room temperature remains elusive. Here, we address this long-standing challenge by implanting dilute Co atoms into few-layer black phosphorus through atomically-thin boron nitride diffusion barrier. Our Co-doped black phosphorus-based devices exhibit ferromagnetism up to room temperature while preserving its high mobility (similar to 1000cm(2)V(-1)s(-1)) and semiconducting characteristics. By incorporating ferromagnetic Co-doped black phosphorus into magnetic tunnel junction devices, we demonstrate a large tunnelling magnetoresistance that extends up to room temperature. This study presents a new approach to engineering ferromagnetic ordering in otherwise nonmagnetic materials, thereby expanding the repertoire and applications of magnetic semiconductors envisioned thus far.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ferromagnetic semiconductors, coupling charge transport and magnetism via electrical means, show great promise for spin-based logic devices. Despite decades of efforts to achieve such co-functionality, maintaining ferromagnetic order at room temperature remains elusive. Here, we address this long-standing challenge by implanting dilute Co atoms into few-layer black phosphorus through atomically-thin boron nitride diffusion barrier. Our Co-doped black phosphorus-based devices exhibit ferromagnetism up to room temperature while preserving its high mobility (similar to 1000cm(2)V(-1)s(-1)) and semiconducting characteristics. By incorporating ferromagnetic Co-doped black phosphorus into magnetic tunnel junction devices, we demonstrate a large tunnelling magnetoresistance that extends up to room temperature. This study presents a new approach to engineering ferromagnetic ordering in otherwise nonmagnetic materials, thereby expanding the repertoire and applications of magnetic semiconductors envisioned thus far.
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Nikolaev, Konstantin G; Grebenchuk, Sergey; Jinpei, Zhao; Yang, Kou; Zhang, Yixin; Shan, Ong Mei; Sorokin, Vitaly; Chen, Siyu; Wang, Qian; Bong, Jia Hui; Novoselov, Kostya S; Andreeva, Daria V Graphene-Based Oscillators for Biomimetic Neuro-Interfaces ADVANCED ELECTRONIC MATERIALS, 11 (15), 2025, DOI: 10.1002/aelm.202500219. @article{WOS:001530117400001, title = {Graphene-Based Oscillators for Biomimetic Neuro-Interfaces}, author = {Konstantin G Nikolaev and Sergey Grebenchuk and Zhao Jinpei and Kou Yang and Yixin Zhang and Ong Mei Shan and Vitaly Sorokin and Siyu Chen and Qian Wang and Jia Hui Bong and Kostya S Novoselov and Daria V Andreeva}, doi = {10.1002/aelm.202500219}, times_cited = {2}, issn = {2199-160X}, year = {2025}, date = {2025-09-01}, journal = {ADVANCED ELECTRONIC MATERIALS}, volume = {11}, number = {15}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {Chemical oscillators-such as the Belousov-Zhabotinsky reaction-have long served as model systems for studying non-equilibrium chemical dynamics and as analogues of biological oscillations. However, many biological processes rely on out-of-equilibrium, often oscillatory, ionic fluxes that do not involve chemical reactions. Examples include action potentials in neurons, muscle contraction, cardiac rhythmicity, intracellular calcium signaling, and calcium wave oscillations. Despite these parallels, the development of biomimetic systems compatible with neuromorphic interfaces remains a significant challenge. Here, a strategy is demonstrated to organize oscillating ionic currents by developing ionic transistors composed of graphene oxide and polyelectrolyte, and assembling them into all-ionic integrated circuits. By driving these systems out of equilibrium using external voltages, periodic motion of various ions across defined interfaces is achieved. This behavior, governed by local electric fields arising from unbalanced ionic concentrations, closely mimics biological excitability, such as that observed in neuronal and cardiac systems. These ionic transistors serve as a foundational building block for neuromorphic interfaces, offering a universal platform to emulate complex biological ionic processes with high fidelity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Chemical oscillators-such as the Belousov-Zhabotinsky reaction-have long served as model systems for studying non-equilibrium chemical dynamics and as analogues of biological oscillations. However, many biological processes rely on out-of-equilibrium, often oscillatory, ionic fluxes that do not involve chemical reactions. Examples include action potentials in neurons, muscle contraction, cardiac rhythmicity, intracellular calcium signaling, and calcium wave oscillations. Despite these parallels, the development of biomimetic systems compatible with neuromorphic interfaces remains a significant challenge. Here, a strategy is demonstrated to organize oscillating ionic currents by developing ionic transistors composed of graphene oxide and polyelectrolyte, and assembling them into all-ionic integrated circuits. By driving these systems out of equilibrium using external voltages, periodic motion of various ions across defined interfaces is achieved. This behavior, governed by local electric fields arising from unbalanced ionic concentrations, closely mimics biological excitability, such as that observed in neuronal and cardiac systems. These ionic transistors serve as a foundational building block for neuromorphic interfaces, offering a universal platform to emulate complex biological ionic processes with high fidelity.
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