Karakterizacija superprevodne pomnilniške celice na podlagi ureditve naboja

BREZEC, BOR (author), Lipovšek, Benjamin (mentor), Mraz, Anže (co-mentor)

V magistrski nalogi je predstavljeno raziskovalno delo na pomnilniški celici paralelotron (pTron), ki zaradi edinstvenih lastnosti ponuja rešitev za pomanjkanje pomnilniške tehnologije v krioračunalništvu, kjer so zahteve po energijski učinkovitosti zelo visoke. Plastoviti material tantalov disulfid, ki je aktiven material v tej pomnilniški celici, pri temperaturah nižjih od 20 K omogoča trajno pomnjenje v obliki izjemno hitrega in energetsko učinkovitega preklapljanja med izolatorskim in kovinskim stanjem z uporabo električnih pulzov. Celica pTron zajema vzporedno vezavo pomnilniške naprave CCM (ang. charge configuration memory), ki temelji na TaS2, in superprevodnega ojačevalne naprave nanokriotron (nTron), ki skrbi za naslavljanje naprave CCM, ojačitev gonilnih signalov in omogoča sklopitev pTron naprave s SFQ (ang. single flux quantum) logiko. Za raziskave je bilo potrebno zasnovati namensko merilno postavitev in razviti programsko opremo za usklajevanje med več različnimi merilnimi instrumenti. S pomočjo merilne postavitve smo karakterizirali več vzorcev CCM in nTron. Izkazalo se je, da šum negativno vpliva na delovanje celice, zato je bilo veliko časa namenjenega njegovemu zmanjševanju. Na podlagi pridobljenih podatkov smo iz naprav CCM in nTron sestavili pomnilniško celico pTron, na kateri smo prvič delno uspešno demonstrirali postopek pisanja. Z uporabo 1 µs dolgega napetostnega pulza smo vzorcu spremenili električno upornost s 6,90 kΩ na 1,78 kΩ, kar je zadovoljivo, vendar pušča še veliko možnosti za izboljšave. Na podlagi teh dognanj je pričakovano nadaljnje raziskovalno delo na pomnilniški celici pTron.

• Language: Slovenian
• Keywords: pomnilniška celica, ultrahiter pomnilnik, TaS2, nTron, pTron
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2024
• PID: 20.500.12556/RUL-153966
• COBISS.SI-ID: 181950723
• Publication date in RUL: 17.01.2024

Secondary language

• Language: English
• Title: Characterization of a superconducting charge configuration memory cell

Abstract

This master thesis presents research work on the parallelotron (pTron) memory cell, which, due to its unique properties, offers a solution to the lack of memory technology in cryo-computing, where the energy efficiency requirements are very high. Tantalum disulphide is a layered material that is the active material in the memory cell. It is capable of persistent data storage at temperatures below 20 K in the form of extremely fast and energy-efficient switching between insulator and metallic states using electrical pulses. The pTron cell comprises a TaS2-based charge configuration memory (CCM) device in parallel with a superconducting nanocryotron (nTron) amplifier device, which addresses the CCM device, amplifies the driving signals and enables the coupling of the pTron cell with single flux quantum (SFQ) logic. To carry out the measurements, a dedicated measurement set-up had to be designed and software for controlling multiple different instruments developed. The set-up was used to characterise several different CCM and nTron samples. Noise has been shown to have a negative impact on cell performance, so a lot of time has been spent on reducing it. Based on the data obtained, we assembled a pTron memory cell from CCM and nTron devices and demonstrated the writing process for the first time with partial success. Using a 1µs long voltage pulse, we changed the electrical resistance of the sample from 6.90kΩ to 1.78kΩ, which is satisfactory but leaves room for improvement. Based on these findings, further research work on the pTron memory cell is to be expected.

• Keywords: memory cell, ultrafast memory, TaS2, nTron, pTron