Nikolaos Vasileiadis

dblp:154/7837 · DBLP profile ↗
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5ranked-venue papers
2as first author
5since 2021 · last 2022
0000-0002-6245-7220ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Systems, architecture and hardware · 5 · 2 first-author · 5 since 2021
YearPublicationVenuePosition
2022 Substrate Effect on Low-frequency Noise of synaptic RRAM devices
abstract
The analysis of noise signals produced by semiconductor devices provides significant information for the origin and the physical mechanisms causing them, allowing for the mitigation of the noise sources, and improving the device performance. Furthermore, noise signals generated by RRAM and memristive devices can be utilized in cryptography security for applications due to their stochastic nature, revealing the positive effects of noise signals. In this work, the noise signals originated from metal-nitride-semiconductor memristive devices are investigated in terms of the influence of the wafer substrate used to fabricate them. Specifically, metal-insulator-semiconductor memristive devices on bulk Si and Silicon-On-Insulator substrates are examined. Parameter extraction and statistical analyses are performed assuming the typical models used for MOSFET devices. Preliminary results suggest that the measured noise signals originated from electron traps sited in the silicon nitride resistance switching layer. However, devices on SOI substrate generate lower noise signals compared to bulk devices, probably due to the better isolation of the active layer.
Nikolaos Vasileiadis, Alexandros Mavropoulis, Panagiotis Loukas, Pascal Normand, Georgios Ch. Sirakoulis, Panagiotis Dimitrakis
VLSI-SoC1
2022 Memristor Crossbar Arrays Performing Quantum Algorithms
abstract
There is a growing interest in quantum computers and quantum algorithm development. It has been proved that ideal quantum computers, with zero error rates and large decoherence times, can solve problems that are intractable for today’s classical computers. Quantum computers use two resources, superposition and entanglement, that have no classical analog. Since quantum computer platforms that are currently available comprise only a few dozen of qubits, the use of quantum simulators is essential in developing and testing new quantum algorithms. We present a novel quantum simulator based on memristor crossbar circuits and use them to simulate well-known quantum algorithms, namely the Deutsch and Grover quantum algorithms. In quantum computing the dominant algebraic operations are matrix-vector multiplications. The execution time grows exponentially with the simulated number of qubits, causing an exponential slowdown in quantum algorithm execution using classical computers. In this work, we show that the inherent characteristics of memristor arrays can be used to overcome this problem and that memristor arrays can be used not only as independent quantum simulators but also as a part of a quantum computer stack where classical computers accelerators are connected. Our memristive crossbar circuits are re-configurable and can be programmed to simulate any quantum algorithm.
Iosif-Angelos Fyrigos, Vasileios G. Ntinas, Nikolaos Vasileiadis, Georgios Ch. Sirakoulis, Panagiotis Dimitrakis, Yue Zhang 0010, Ioannis Karafyllidis
IEEE Trans. Circuits Syst. I Regul. Pap.3
2021 Memristor Crossbar Design Framework for Quantum Computing
abstract
Over the last years there has been significant progress in the development of quantum computers. It has been demonstrated that they can accelerate the solution of various problems exponentially compared to today's classical computers, harnessing the properties of superposition and entanglement, two resources that have no classical analog. Since quantum computer platforms that are currently available comprise only a few tenths of qubits, as well as the access to a fabricated quantum computer is time limited for the majority of researchers, the use of quantum simulators is essential in developing and testing new quantum algorithms. Taking inspiration from previous work on developing a novel quantum simulator based on memristor crossbar circuits, in this work, a framework that automates the circuit design of emulated quantum gates is presented. The proposed design framework deals with the generation and programming of memristor crossbar configuration that incorporates the desirable quantum circuit, leading to a technology agnostic design tool. To such a degree, various quantum gates can be efficiently emulated on memristor crossbar configurations for various types of memristive devices, aiming to assist and accelerate the fabrication process of a memristor based quantum simulator.
Iosif-Angelos Fyrigos, Theodoros Panagiotis Chatzinikolaou, Vasileios G. Ntinas, Nikolaos Vasileiadis, Panagiotis Dimitrakis, Ioannis Karafyllidis, Georgios Ch. Sirakoulis
ISCAS4
2021 Emergence of Chimera States with Re-Programmable Memristor Crossbar Arrays
abstract
The time series of the brain are usually characterized by the co-existence of synchronized and desynchronized behaviors. This kind of behavior is related to normal and disorderly functions of the brain. One of the suggested mechanisms to understand thoroughly this behavior are chimera states, which are characterized by the coincidence of coherent and incoherent dynamics that can be exploited through networks of symmetrically coupled identical oscillators. In this work, ring-based networks of Chua's circuits, the simplest electronic oscillators that perform chaotic and well-known bifurcation phenomena, have been extensively studied in memristive crossbars (Xbar), revealing various collective spatio-temporal behaviors, such as chimera states. With respect to different Xbar connectivities and via SPICE-level circuit simulations, the proposed Xbar system proves its efficacy to reproduce spatio-temporal patterns spanning from complete synchronization and chimera states up to fully chaotic states.
Karolos-Alexandros Tsakalos, Vasileios G. Ntinas, Rafailia-Eleni Karamani, Iosif-Angelos Fyrigos, Theodoros Panagiotis Chatzinikolaou, Nikolaos Vasileiadis, Panagiotis Dimitrakis, Astero Provata, Georgios Ch. Sirakoulis
ISCAS6
2021 A New 1P1R Image Sensor with In-Memory Computing Properties Based on Silicon Nitride Devices
abstract
Research progress in edge computing hardware, capable of demanding in-the-field processing tasks with simultaneous memory and low power properties, is leading the way towards a revolution in IoT hardware technology. Resistive random access memories (RRAM) are promising candidates for replacing current non-volatile memories and realize storage class memories, but also due to their memristive nature they are the perfect candidates for in-memory computing architectures. In this context, a CMOS compatible silicon nitride (SiN) device with memristive properties is presented accompanied by a data-fitted model extracted through analysis of measured resistance switching dynamics. Additionally, a new phototransistor-based image sensor architecture with integrated SiN memristor (1P1R) was presented. The in-memory computing capabilities of the 1P1R device were evaluated through SPICE-level circuit simulation with the previous presented device model. Finally, the fabrication aspects of the sensor are discussed.
Nikolaos Vasileiadis, Vasileios G. Ntinas, Iosif-Angelos Fyrigos, Rafailia-Eleni Karamani, Vassilios Ioannou-Sougleridis, Pascal Normand, Ioannis Karafyllidis, Georgios Ch. Sirakoulis, Panagiotis Dimitrakis
ISCAS1