Guy Le Lay

Guy Le Lay

Aix-Marseille Université

H-index: 58

Europe-France

About Guy Le Lay

Guy Le Lay, With an exceptional h-index of 58 and a recent h-index of 27 (since 2020), a distinguished researcher at Aix-Marseille Université, specializes in the field of Nanosciences Surface Science Synchrotron Radiation.

His recent articles reflect a diverse array of research interests and contributions to the field:

Group IV Xenes quantum designer

Core photoemission from graphene to silicene

Spin polarized Majorana zero modes in penta-silicene nanoribbons

Dirac fermions in germanene: bottom-up versus top-down approaches

Bruno Touschek and the birth of collider physics: an extraordinary journey

Formation of germanene with free-standing lattice constant

Spin-polarized Majorana zero modes in proximitized superconducting penta-silicene nanoribbons

The Renaissance and Golden Age of Epitaxial Dry Germanene

Guy Le Lay Information

University

Aix-Marseille Université

Position

___

Citations(all)

17629

Citations(since 2020)

5173

Cited By

14838

hIndex(all)

58

hIndex(since 2020)

27

i10Index(all)

165

i10Index(since 2020)

57

Email

University Profile Page

Aix-Marseille Université

Guy Le Lay Skills & Research Interests

Nanosciences Surface Science Synchrotron Radiation

Top articles of Guy Le Lay

Group IV Xenes quantum designer

Authors

Guy Le Lay

Published Date

2023

After the advent of graphene and other two-dimensional (2D) materials that could be directly peeled from natural 3D crystals, a paradigmatic shift was the creation of Silicene, the first artificial 2D crystal, synthesized in 2012. Since then, a number of offsprings, coined Xenes, ie, monoelemental analogues, have emerged from the lightest Beryllene to the heaviest Bismuthene. Among those, the new 2D forms of Ge, Sn, and Pb coined Germanene, Stanene and Plumbene, have attracted huge interest, especially because they possess sizeable spin-orbit couplings, allowing for the quantum spin Hall effect, possibly at room temperature and even above. 2D topological insulators may lead to breakthrough applications from Field-Effect Transistors to spintronics. Group IV Xenes are also considered for improved lithium/sodium batteries, solar cells, and for hydrogen storage, while major applications are also envisaged in nanobiology, nanomedicine and for cancer cell theranostics. 1D nanoribbons, may host Majorana zero modes at their ends, which could be crucial for quantum computation. In my talk I will recall how Silicene was designed and describe the striking emergent properties of several Xenes, especially those of Germanene, Stanene and Plumbene, as well as their outstanding multifaceted outcomes.

Core photoemission from graphene to silicene

Authors

Paola De Padova,Paolo Perfetti,Guy Le Lay

Published Date

2023/1/1

Core-level photoemission has been and remains one of the most powerful spectroscopic techniques for studying the structure and properties of condensed matter. With the advent of high-resolution instrumentation, for both electron analyzers and photon sources, coupled to large accelerating machines such as synchrotrons, core photoemission spectroscopy (CPS) has revealed its great potential, notably in the study of surfaces and interfaces prepared in ultra-high vacuum.Through peak fitting procedures, CPS performed on graphene and its first Xene siblings (two-dimensional elemental artificial materials), namely, silicene, we will retrace remarkable discoveries, where core-level photoemission has played a major role.

Spin polarized Majorana zero modes in penta-silicene nanoribbons

Authors

Marcos Sergio Figueira Silva,Renan Bento Campos,Jorge Correa,Luciano Ricco,Ivan Shelykh,Mucio Continentino,Antonio Seridonio,Guy Lay

Journal

APS March Meeting Abstracts

Published Date

2023

In the present work, we study the possibility of obtaining Majorana zero modes (MZMs) in penta-silicene nanoribbons (p-SINRs), following the same procedure as our previous work. The spinless and spin full p-SINR with p-wave superconducting pairing reveals the emergence of topologically protected MZMs at opposite edges of the p-SINR. We consider an external magnetic field perpendicularly applied to the nanoribbon plane and an extrinsic Rashba spin-orbit coupling (RSOC), besides the first nearest neighbor hopping term and p-wave superconducting pairing. The dispersion relation profiles show the closing and reopening of the superconducting gap for only one spin component, suggesting a spin-polarized topological phase transition (TPT). Associated with these TPTs, the energy spectrum as a function of the p-SINR chemical potential exhibits zero-energy states and preferential spin direction. It is …

Dirac fermions in germanene: bottom-up versus top-down approaches

Authors

Guy Le Lay,Marco Minissale,Eric Salomon,Thierry Angot,PS Team

Journal

APS March Meeting Abstracts

Published Date

2023

Germanene is an artificial two-dimensional graphene-like germanium allotrope predicted to be a near room temperature topological insulator, belonging to the class of so-called Xenes. It was synthesized in 2014, exactly ten years after the isolation of graphene, and just two years after the archetype growth of silicene, the first Xene ever produced. The canonical germanene paper, described its top-down synthesis by Ge deposition onto a Au (111) crystal, but revealed multi-phases. Instead, we will show that a single germanene phase, as evidenced in Scanning Tunneling Microscopy in situ imaging, is obtained by Ge segregation on top of a thin Au (111) film epitaxially grown under ultra-high vacuum on a Ge (111) template, that is, through a bottom-up approach. This segregation process was directly vizualized ex-situ in high-resolution Scanning Electron Microscopy. The most striking signature of this single …

Bruno Touschek and the birth of collider physics: an extraordinary journey

Authors

Giulia Pancheri-Srivastava

Journal

APS March Meeting Abstracts

Published Date

2023

I will describe new findings about the Austrian born scientist Bruno Touschek, who in 1960 proposed and built in Italy the first ever electron-positron collider. A recently published biography and the Proceedings of a Memorial Symposium, held in Rome in December 2021 one hundred years after his birth in Vienna on 3 February 1921, highlight Touschek's scientific work and the three particle accelerators he brought to success, from Rolf Wideroe's betatron in 1944, to the e+ e-colliders AdA and ADONE in the 1960's. Touschek's life spanned Europe in space and time, from racial discrimination, because his mother was Jewish, to the years of European reconstruction. After escaping deportation to the Kiel concentration camp in April 1945, Touschek pursued his studies in Goettingen, where he was Heisenberg's assistant in 1946, and in Glasgow, where he was befriended by Max Born, and received his PhD, with …

Formation of germanene with free-standing lattice constant

Authors

Junji Yuhara,Daiki Matsuba,Masaki Ono,Akio Ohta,Seiichi Miyazaki,Masaaki Araidai,Sho-ichi Takakura,Masashi Nakatake,Guy Le Lay

Journal

Surface Science

Published Date

2023/12/1

Two-dimensional sheets of ultra-thin germanium with the lattice parameter of free-standing germanene, ie, 0.41 nm, are formed by atomic segregation epitaxy on face-centered-cubic Ag 0.9 Al 0.1 (111) thin films grown on a Ge (111) template. Low-energy electron diffraction clearly shows a square-like (√ 13×√ 13) R±46° superstructure, expressed as (4 1 1 4) in Matrix form, whose 92° angle between the two vectors is clearly observed, as well as incommensurate (1.41× 1.41) R±27° spots. Scanning tunneling microscopy (STM) images show the square-like superstructure and a defective honeycomb-like arrangement with this characteristic 0.41 nm lattice constant, corresponding to LEED patterns. Complimentary high-resolution synchrotron radiation photoemission spectroscopy measurements reveal the electronic structure of the honeycomb-like germanene sheet and further demonstrate that it overlays the surface …

Spin-polarized Majorana zero modes in proximitized superconducting penta-silicene nanoribbons

Authors

RC Bento Ribeiro,JH Correa,LS Ricco,IA Shelykh,Mucio A Continentino,AC Seridonio,M Minissale,G Le Lay,MS Figueira

Journal

Scientific Reports

Published Date

2023/10/20

We theoretically propose penta-silicene nanoribbons (p-SiNRs) with induced p-wave superconductivity as a platform for the emergence of spin-polarized Majorana zero-modes (MZMs). The model explicitly considers the key ingredients of well-known Majorana hybrid nanowire setups: Rashba spin-orbit coupling, magnetic field perpendicular to the nanoribbon plane, and first nearest neighbor hopping with p-wave superconducting pairing. The energy spectrum of the system, as a function of chemical potential, reveals the existence of MZMs with a well-defined spin orientation localized at the opposite ends of both the top and bottom chains of the p-SiNR, associated with well-localized and nonoverlapping wave function profiles. Well-established experimental techniques enable the fabrication of highly ordered p-SiNRs, complemented by a thin lead film on top, responsible for inducing p-wave superconductivity …

The Renaissance and Golden Age of Epitaxial Dry Germanene

Authors

Marco Minissale,Eric Salomon,Federica Pappalardo,Céline Martin,Matthias Muntwiler,Thierry Angot,Guy Le Lay

Published Date

2023/1/25

Germanene, as an artificial graphene-like near room temperature topological insulator, compatible with ubiquitous silicon technology, is potentially the most promising artificial Xene for ultra-scale nanoelectronics. Here, we follow its emergence and development when prepared in situ under ultra-high vacuum in clean and controlled conditions by dry epitaxy on prominent metal surfaces (e.g., aluminum, silver, gold). We describe its predicted electronic properties and its birth in 2014, even if it was just a renaissance, as it was only understood after 51 years after an undeciphered birth certificate lost in oblivion. We emphasize the lifting of germanene flakes from an aluminum template with the tip of a scanning tunneling microscope, and their repositioning to form bilayer germanene with Bernal stacking. Finally, we discuss the growth of monolayer germanene in a single phase harboring Dirac fermions, following a bottom-up synthesis strategy by segregation on a gold thin film in epitaxy on a germanium support.

Silicene: Genesis, remarkable discoveries, and legacy

Authors

María E Dávila,Guy Le Lay

Published Date

2022/12/1

In the realm of two-dimensional (2D) materials, besides the ones initially peeled from lamellar crystals, the artificial emerging elemental ones, called Xenes, appear as strong contenders to graphene in a booming new field. The very first synthetic Xene was silicene, created in 2012. On the occasion of its tenth anniversary, this concise review, describes the birth of silicene, in situ, under ultra-high vacuum, and surveys its most tantalizing properties: its Dirac features, its 2D topological insulator character, its easy functionalization, its insertion as atom-thin channel in Field Effect Transistors operating at room temperature. Silicene has striking variants and amazing doubles in the quantum world; these lookalikes are briefly described and their origins discussed. We owe to silicene the legacy of all its descendants from borophene to tellurene, and fascinating prospects for spintronics, the emergence and control of Majorana …

Silicene

Authors

Eric Salomon,Thierry Angot,Lok Lew Yan Voon,Guy Le Lay

Published Date

2022/1/1

The possibility of a corrugated, atomically thin, honeycomb silicon sheet, theoretically envisaged in 1994, 10 years before the advent of graphene, has been experimentally demonstrated for the first time in 2012. The fascinating “flower pattern” observed in scanning tunneling microscopy upon epitaxial growth of Si on a silver (1 1 1) surface masked a unique honeycomb arrangement of silicon atoms. Initially guessed, this hidden atomic geometry has been supported by density functional theory calculations and photoemission measurements, while directly evidenced later by near-contact atomic force microscopy. The realization of silicene and the demonstration of its outstanding properties have further engendered a large filiation of Xenes, namely, elemental artificial two-dimensional cousins, from borophene to bismuthene. In this chapter we relate the birth of silicene and of its variants, penta-silicene and kagome …

Single germanene phase formed by segregation through Al (111) thin films on Ge (111)

Authors

Junji Yuhara,Hiroaki Muto,Masaaki Araidai,Masato Kobayashi,Akio Ohta,Seiichi Miyazaki,Sho-ichi Takakura,Masashi Nakatake,Guy Le Lay

Journal

2D Materials

Published Date

2021/10/12

We have obtained single phase monolayer germanene on aluminum (111) thin films grown on a germanium (111) template by atomic segregation epitaxy, a preparation method differing from molecular beam epitaxy used in previous works. This 2× 2 reconstructed germanene phase matching an Al (111) 3× 3 supercell has been prepared in large areas upon annealing at 430 C. Detailed studies have been carried out using scanning tunneling microscopy (STM), low-energy electron diffraction, Auger electron spectroscopy, and synchrotron radiation photoemission spectroscopy. First-principles calculations based on the density function theory along with atomic-scale STM images reveal the atomic structure with one protruding Ge atom per 2× 2 germanene supercell and a characteristic dispersing band originating from the germanene sheet slightly coupled to the first layer Al atoms underneath. Instead, upon …

Epitaxial growth of massively parallel germanium nanoribbons by segregation through Ag (1 1 0) thin films on Ge (1 1 0)

Authors

Junji Yuhara,Hiroki Shimazu,Masato Kobayashi,Akio Ohta,Seiichi Miyazaki,Sho-ichi Takakura,Masashi Nakatake,Guy Le Lay

Journal

Applied Surface Science

Published Date

2021/6/1

We investigate the epitaxial growth of low-dimensional nanostructures formed by surface segregation of germanium on single crystalline Ag(1 1 0) thin films supported by a Ge(1 1 0) template. Detailed studies of the atomic geometries have been carried out using scanning tunneling microscopy, low-energy electron diffraction, Auger electron spectroscopy, and high-resolution synchrotron radiation core-level spectroscopy. At very low Ge coverages the segregated Ge atoms form two kinds of commensurate and incommensurate quantum structures after annealing. With increasing Ge coverages, narrow stripes, 0.5 nm in width and with lengths ranging from 5 nm to 50 nm, are formed. With further increase of the Ge atoms’ segregation on the surface, the narrow stripes transform into massively parallel one-dimensional Ge nanostructures with specific widths. From a combined analysis, these fascinating quantum …

In-plane strain-free stanene on a surface alloy

Authors

Junji Yuhara,Tsuyoshi Ogikubo,Masaaki Araidai,Sho-ichi Takakura,Masashi Nakatake,Guy Le Lay

Journal

Physical Review Materials

Published Date

2021/5/19

Here we report the growth of laterally strain-free stanene, that is a two-dimensional (2D) honeycomb structure of tin atoms, on a Pd (111) crystal terminated by a Pd 2 Sn surface alloy. The atomic geometry and the electronic structure have been thoroughly investigated by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), Auger electron spectroscopy, high-resolution synchrotron radiation photoemission spectroscopy, and advanced first principles calculations. The STM images clearly reveal the epitaxial growth of honeycomb stanene on the preformed Pd 2 Sn surface alloy. LEED patterns clearly show commensurate (√ 3×√ 3) R30 spots, corresponding to a lattice constant of 0.47 nm, in perfect accord with the cell size of free-standing stanene. The measured very low buckling, within 20 pm, is derived from section profiles of atomic-scale STM images. This contrasts the significantly larger …

Kagome-like silicene: A novel exotic form of two-dimensional epitaxial silicon

Authors

Yasmine Sassa,Fredrik OL Johansson,Andreas Lindblad,Milad G Yazdi,Konstantin Simonov,Jonas Weissenrieder,Matthias Muntwiler,Fadil Iyikanat,Hasan Sahin,Thierry Angot,Eric Salomon,Guy Le Lay

Journal

Applied Surface Science

Published Date

2020/11/15

Since the discovery of graphene, intensive efforts have been made in search of novel two-dimensional (2D) materials. Decreasing the materials dimensionality to their ultimate thinness is a promising route to unveil new physical phenomena, and potentially improve the performance of devices. Among recent 2D materials, analogs of graphene, the group IV elements have attracted much attention for their unexpected and tunable physical properties. Depending on the growth conditions and substrates, several structures of silicene, germanene, and stanene can be formed. Here, we report the synthesis of a Kagome-like lattice of silicene on aluminum (1 1 1) substrates. We provide evidence of such an exotic 2D Si allotrope through scanning tunneling microscopy (STM) observations, high-resolution core-level (CL) and angle-resolved photoelectron spectroscopy (ARPES) measurements, along with Density Functional …

Epitaxial growth of honeycomb-like stanene on Au (111)

Authors

Wenhui Pang,Kazuki Nishino,Tsuyoshi Ogikubo,Masaaki Araidai,Masashi Nakatake,Guy Le Lay,Junji Yuhara

Journal

Applied Surface Science

Published Date

2020/7/1

Stanene, which is predicted to be a quantum spin Hall topological insulator with tunable topological state, seems to be the most promising candidate of the post-graphene elemental two-dimensional (2D) materials. Here, we prepared epitaxial honeycomb-like stanene on gold (111) substrates and investigated its superstructure by Low Energy Electron Diffraction and Scanning Tunneling Microscopy. Angle-Resolved PhotoEmission Spectroscopy was applied to explore the electronic structures, further confirmed by first principles calculations. The stanene-like sheet forms a nearly planar structure on the Au(111) surface with a “2×√3” superstructure in large surface areas. Core-level spectroscopy reveals that the stanene-like sheet lays almost directly on the Au(111) surface. This is consistent with DFT calculations of the atomic structure. A characteristic 2D band with parabolic dispersion is observed.

Continuous growth of germanene and stanene lateral heterostructures

Authors

Tsuyoshi Ogikubo,Hiroki Shimazu,Yuya Fujii,Koichi Ito,Akio Ohta,Masaaki Araidai,Masashi Kurosawa,Guy Le Lay,Junji Yuhara

Journal

Advanced Materials Interfaces

Published Date

2020/5

Group 14 elemental post‐graphene materials receive much attention because of their outstanding properties, typically, as robust 2D topological insulators. Their heterostructures are a main target in view of disruptive applications. Here, the realization of striking in‐plane lateral heterostructures between germanene and stanene are shown, which are sustainable 2D Ge‐ and Snbased graphene analogs, but with a strong intrinsic spin–orbit coupling. A unique combination of atomic segregation epitaxy (ASE) and molecular beam epitaxy (MBE) for the in situ continuous fabrication of nearly atomically precise lateral multijunction heterostructures, respectively, consisting of atom‐thin germanene and stanene on a Ag(111) thin film is used. Scanning tunneling microscopy (STM) observations at atomic scale and low‐energy electron diffraction testify that germanene and stanene sheets without intermixing are prepared …

Beyond silicene: synthesis of germanene, stanene and plumbene

Authors

Junji Yuhara,Guy Le Lay

Journal

Japanese Journal of Applied Physics

Published Date

2020/4/23

Twenty five years after the first theoretical prediction of two-dimensional (2D) honeycomb-like silicon and germanium, now coined silicene and germanene, the last Group 14 artificial cousin of graphene has been synthesized, thus terminating the lineage from silicene (2012) to germanene (2014), stanene (2015), and finally plumbene (2019). Here, we describe the realizations and review the tantalizing properties of these outstanding novel 2D materials.

Reducing the dimensionality of novel materials: one-dimensional silicon nanoribbons

Authors

ME Dávila,G Le Lay,J Cerdá

Published Date

2020/1/1

Our group has revealed an unprecedented one-dimensional (1D) Si atomic arrangement solely comprising highly perfect alternating pentagons residing in the missing row troughs of the reconstructed surface Ag(1 1 0). It is the first pure pentagonal phase ever found for silicon low-dimensional structures, initially theoretically supported by density functional theory (DFT) calculations compared to scanning tunneling microscopy observations, further rapidly confirmed by surface X-ray diffraction measurements. In fact, until now such a structure has only been obtained synthetically as 1D nanoribbons (1D-NRs) grown on a silver (1 1 0) substrate. These NRs adopt a highly ordered chiral arrangement in single- and/or double-strands. We thus simultaneously demonstrate the existence of penta-silicene, a recently conjectured novel pentagonal silicon allotrope, which remained unveiled for more than one decade, and …

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Guy Le Lay FAQs

What is Guy Le Lay's h-index at Aix-Marseille Université?

The h-index of Guy Le Lay has been 27 since 2020 and 58 in total.

What are Guy Le Lay's top articles?

The articles with the titles of

Group IV Xenes quantum designer

Core photoemission from graphene to silicene

Spin polarized Majorana zero modes in penta-silicene nanoribbons

Dirac fermions in germanene: bottom-up versus top-down approaches

Bruno Touschek and the birth of collider physics: an extraordinary journey

Formation of germanene with free-standing lattice constant

Spin-polarized Majorana zero modes in proximitized superconducting penta-silicene nanoribbons

The Renaissance and Golden Age of Epitaxial Dry Germanene

...

are the top articles of Guy Le Lay at Aix-Marseille Université.

What are Guy Le Lay's research interests?

The research interests of Guy Le Lay are: Nanosciences Surface Science Synchrotron Radiation

What is Guy Le Lay's total number of citations?

Guy Le Lay has 17,629 citations in total.