| Records |
| Author |
Vermeulen, B.B.; Raymenants, E.; Pham, V.T.; Pizzini, S.; Sorée, B.; Wostyn, K.; Couet, S.; Nguyen, V.D.; Temst, K. |
| Title |
Towards fully electrically controlled domain-wall logic |
Type |
A1 Journal article |
Year  |
2024 |
Publication |
AIP advances |
Abbreviated Journal |
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| Volume |
14 |
Issue |
2 |
Pages |
025030-25035 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Utilizing magnetic tunnel junctions (MTJs) for write/read and fast spin-orbit-torque (SOT)-driven domain-wall (DW) motion for propagation, enables non-volatile logic and majority operations, representing a breakthrough in the implementation of nanoscale DW logic devices. Recently, current-driven DW logic gates have been demonstrated via magnetic imaging, where the Dzyaloshinskii-Moriya interaction (DMI) induces chiral coupling between perpendicular magnetic anisotropy (PMA) regions via an in-plane (IP) oriented region. However, full electrical operation of nanoscale DW logic requires electrical write/read operations and a method to pattern PMA and IP regions compatible with the fabrication of PMA MTJs. Here, we study the use of a Hybrid Free Layer (HFL) concept to combine an MTJ stack with DW motion materials, and He+ ion irradiation to convert the stack from PMA to IP. First, we investigate the free layer thickness dependence of 100-nm diameter HFL-MTJ devices and find an optimal CoFeB thickness, from 7 to 10 angstrom, providing high tunneling magnetoresistance (TMR) readout and efficient spin-transfer torque (STT) writing. We then show that high DMI materials, like Pt/Co, can be integrated into an MTJ stack via interlayer exchange coupling with the CoFeB free layer. In this design, DMI values suitable for SOT-driven DW motion are measured by asymmetric bubble expansion. Finally, we demonstrate that He+ irradiation reliably converts the coupled free layers from PMA to IP. These findings offer a path toward the integration of fully electrically controlled DW logic circuits. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001163573400005 |
Publication Date |
2024-02-16 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2158-3226 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:203823 |
Serial |
9109 |
| Permanent link to this record |
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| Author |
Raymenants, E.; Bultynck, O.; Wan, D.; Devolder, T.; Garello, K.; Souriau, L.; Thiam, A.; Tsvetanova, D.; Canvel, Y.; Nikonov, D.E.; Young, I.A.; Heyns, M.; Sorée, B.; Asselberghs, I.; Radu, I.; Couet, S.; Nguyen, V.D. |
| Title |
Nanoscale domain wall devices with magnetic tunnel junction read and write |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Nature Electronics |
Abbreviated Journal |
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| Volume |
4 |
Issue |
6 |
Pages |
392-398 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
The manipulation of fast domain wall motion in magnetic nanostructures could form the basis of novel magnetic memory and logic devices. However, current approaches for reading and writing domain walls require external magnetic fields, or are based on conventional magnetic tunnel junctions (MTJs) that are not compatible with high-speed domain wall motion. Here we report domain wall devices based on perpendicular MTJs that offer electrical read and write, and fast domain wall motion via spin-orbit torque. The devices have a hybrid free layer design that consists of platinum/cobalt (Pt/Co) or a synthetic antiferromagnet (Pt/Co/Ru/Co) into the free layer of conventional MTJs. We show that our devices can achieve good tunnelling magnetoresistance readout and efficient spin-transfer torque writing that is comparable to current magnetic random-access memory technology, as well as domain wall depinning efficiency that is similar to stand-alone materials. We also show that a domain wall conduit based on a synthetic antiferromagnet offers the potential for reliable domain wall motion and faster write speed compared with a device based on Pt/Co. Domain wall devices based on perpendicular magnetic tunnel junctions with a hybrid free layer design can offer electrical read and write, and fast domain wall motion driven via spin-orbit torque. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000665011500005 |
Publication Date |
2021-06-23 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2520-1131 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:179673 |
Serial |
7003 |
| Permanent link to this record |
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| Author |
Devolder, T.; Bultynck, O.; Bouquin, P.; Nguyen, V.D.; Rao, S.; Wan, D.; Sorée, B.; Radu, I.P.; Kar, G.S.; Couet, S. |
| Title |
Back hopping in spin transfer torque switching of perpendicularly magnetized tunnel junctions |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
102 |
Issue |
18 |
Pages |
184406 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We analyze the phenomenon of back hopping in spin-torque induced switching of the magnetization in perpendicularly magnetized tunnel junctions. The analysis is based on single-shot time-resolved conductance measurements of the pulse-induced back hopping. Studying several material variants reveals that the back hopping is a feature of the nominally fixed system of the tunnel junction. The back hopping is found to proceed by two sequential switching events that lead to a final state P' of conductance close to-but distinct from-that of the conventional parallel state. The P' state does not exist at remanence. It generally relaxes to the conventional antiparallel state if the current is removed. The P' state involves a switching of the sole spin-polarizing part of the fixed layers. The analysis of literature indicates that back hopping occurs only when the spin-polarizing layer is too weakly coupled to the rest of the fixed system, which justifies a posteriori the mitigation strategies of back hopping that were implemented empirically in spin-transfer-torque magnetic random access memories. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000587594900005 |
Publication Date |
2020-11-09 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
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Open Access |
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| Notes |
; This work was supported in part by the IMEC's Industrial Affiliation Program on STT-MRAM device, and in part by the imec IIAP core CMOS and the Beyond CMOS program of Intel Corporation. T. D. and P. B. thank Jonathan Z. Sun for constructive discussions on the BH phenomenon. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:173524 |
Serial |
6458 |
| Permanent link to this record |
