Abstract:Metallic transition metal dichalcogenides (TMDs) have exhibited various exotic physical properties and hold the promise of novel optoelectronic and topological devices applications. However, the synthesis of metallic TMDs is based on gas-phase methods and requires high-temperature condition. As an alternative to the gas-phase synthetic approach, lower temperature eutectic liquid-phase synthesis presents a very promising approach with the potential for larger-scale and controllable growth of high-quality thin m… Show more
“…PtTe 2 exhibits to date the highest room‐temperature electrical conductivity (≈3.3 × 10 6 S m −1 ) among metallic TMDs. [ 22 ] In addition, PtTe 2 is categorized as a type‐II Dirac semimetal, [ 23,24 ] where the topological nontrivial 2 invariant gives rise to topological surface states (TSSs) with spin‐momentum locking (like the case of topological insulator [ 25,26 ] ). Although the bulk Dirac node of PtTe 2 and its corresponding TSSs are well below the Fermi level (≈−1 eV), another non‐trivial conical dispersion located between Γ and M points were found slightly below the Fermi level in PtTe 2 .…”
Section: Figurementioning
confidence: 99%
“…The range of l ϕ and the electron scattering mechanism in our thin‐film samples are consistent with the results of single‐crystal PtTe 2 . [ 22 ]…”
Spin-orbit torque (SOT) provides an ultrafast and energy-efficient means to switch magnetization, which is of fundamental and technical importance for spintronic devices. [1][2][3][4][5] A typical SOT device consists of heavy metal/ferromagnet (HM/FM) bilayer, where the HM (e.g., Pt, W, Ta, etc.) converts charge current into spin current mainly due to the spin Hall effect (SHE) and then exerts a torque on the adjacent FM enabling magnetization manipulation. To improve the energy efficiency of SOT-driven magnetization switching, considerable efforts have been made to enhance the charge-spin conversion efficiency of HM [6][7][8][9] and reduce the shunting current in the FM. [10,11] Engineering the bilayer structure [9,12] or replacing HM by novel materials with larger charge-spin conversion efficiency and higher conductivity [10,13,14] are possible avenues to realize higher SOT efficiency.
Manipulation of magnetization by electric-current-induced spin-orbit torque (SOT) is of great importance for spintronic applications because of its merits in energy-efficient and high-speed operation. An ideal material for SOT applications should possess high charge-spin conversion efficiency and high electrical conductivity. Recently, transition metal dichalcogenides (TMDs) emerge as intriguing platforms for SOT study because of their controllability in spin-orbit coupling, conductivity, and energy band topology. Although TMDs show great potentials in SOT applications, the present study is restricted to the mechanically exfoliated samples with small sizes and relatively low conductivities.Here, a manufacturable recipe is developed to fabricate large-area thin films of PtTe 2 , a type-II Dirac semimetal, to study their capability of generating SOT. Large SOT efficiency together with high conductivity results in a giant spin Hall conductivity of PtTe 2 thin films, which is the largest value among the presently reported TMDs. It is further demonstrated that the SOT from PtTe 2 layer can switch a perpendicularly magnetized CoTb layer efficiently. This work paves the way for employing PtTe 2 -like TMDs for wafer-scale spintronic device applications.
“…PtTe 2 exhibits to date the highest room‐temperature electrical conductivity (≈3.3 × 10 6 S m −1 ) among metallic TMDs. [ 22 ] In addition, PtTe 2 is categorized as a type‐II Dirac semimetal, [ 23,24 ] where the topological nontrivial 2 invariant gives rise to topological surface states (TSSs) with spin‐momentum locking (like the case of topological insulator [ 25,26 ] ). Although the bulk Dirac node of PtTe 2 and its corresponding TSSs are well below the Fermi level (≈−1 eV), another non‐trivial conical dispersion located between Γ and M points were found slightly below the Fermi level in PtTe 2 .…”
Section: Figurementioning
confidence: 99%
“…The range of l ϕ and the electron scattering mechanism in our thin‐film samples are consistent with the results of single‐crystal PtTe 2 . [ 22 ]…”
Spin-orbit torque (SOT) provides an ultrafast and energy-efficient means to switch magnetization, which is of fundamental and technical importance for spintronic devices. [1][2][3][4][5] A typical SOT device consists of heavy metal/ferromagnet (HM/FM) bilayer, where the HM (e.g., Pt, W, Ta, etc.) converts charge current into spin current mainly due to the spin Hall effect (SHE) and then exerts a torque on the adjacent FM enabling magnetization manipulation. To improve the energy efficiency of SOT-driven magnetization switching, considerable efforts have been made to enhance the charge-spin conversion efficiency of HM [6][7][8][9] and reduce the shunting current in the FM. [10,11] Engineering the bilayer structure [9,12] or replacing HM by novel materials with larger charge-spin conversion efficiency and higher conductivity [10,13,14] are possible avenues to realize higher SOT efficiency.
Manipulation of magnetization by electric-current-induced spin-orbit torque (SOT) is of great importance for spintronic applications because of its merits in energy-efficient and high-speed operation. An ideal material for SOT applications should possess high charge-spin conversion efficiency and high electrical conductivity. Recently, transition metal dichalcogenides (TMDs) emerge as intriguing platforms for SOT study because of their controllability in spin-orbit coupling, conductivity, and energy band topology. Although TMDs show great potentials in SOT applications, the present study is restricted to the mechanically exfoliated samples with small sizes and relatively low conductivities.Here, a manufacturable recipe is developed to fabricate large-area thin films of PtTe 2 , a type-II Dirac semimetal, to study their capability of generating SOT. Large SOT efficiency together with high conductivity results in a giant spin Hall conductivity of PtTe 2 thin films, which is the largest value among the presently reported TMDs. It is further demonstrated that the SOT from PtTe 2 layer can switch a perpendicularly magnetized CoTb layer efficiently. This work paves the way for employing PtTe 2 -like TMDs for wafer-scale spintronic device applications.
“…Growth of PtTe2 thin films with thickness down to a few nanometers has been reported by chemical vapor deposition (CVD) recently [20][21][22]. However, so far there is no report of thinner (sub-nanometer) films and the experimental electronic structure of PtTe2 films still remains to be explored.…”
PtTe 2 and PtSe 2 with trigonal structure have attracted extensive research interests since the discovery of type-II Dirac fermions in the bulk crystals. The evolution of the electronic structure from bulk 3D topological semimetal to 2D atomic thin films is an important scientific question. While a transition from 3D type-II Dirac semimetal in the bulk to 2D semiconductor in monolayer (ML) film has been reported for PtSe 2 , so far the evolution of electronic structure of atomically thin PtTe 2 films still remains unexplored. Here we report a systematic angleresolved photoemission spectroscopy (ARPES) study of the electronic structure of high quality PtTe 2 films grown by molecular beam epitaxy with thickness from 2 ML to 6 ML. ARPES measurements show that PtTe 2 films still remain metallic even down to 2 ML thickness, which is in sharp contrast to the semiconducting property of few layer PtSe 2 film. Moreover, a transition from 2D metal to 3D type-II Dirac semimetal occurs at film thickness of 4-6 ML. In addition, Spin-ARPES measurements reveal helical spin textures induced by local Rashba effect in the bulk PtTe 2 crystal, suggesting that similar hidden spin is also expected in few monolayer PtTe 2 films. Our work reveals the transition from 2D metal to 3D topological semimetal and provides new opportunities for investigating metallic 2D films with local Rashba effect.
“…This newly developed Pt-based TMDs material has strong interlayer interaction 53 and air stability 54,55 . Contrast to the complicated and expensive CVD fabrication method 53,56,57 , the PtTe 2 nanosheets used for this experiment are produced by an uncomplicated and cost-effective ultrasonic liquid exfoliation technique and followed by incorporating within the polyvinyl alcohol (PVA) polymer to form a larger-scale PtTe 2 -PVA saturable absorber. The fabrication method employed here is well suitable for making commercial products.Figure 1The 3D crystal structure of a monolayer PtTe 2 .…”
Two-dimensional (2D) layered Platinum Ditelluride (PtTe
2
), a novel candidate of group 10 transition-metal dichalcogenides (TMDs), which provides enormous potential for pulsed laser applications due to its highly stable and strong nonlinear optical absorption (NOA) properties. PtTe
2
saturable absorber (SA) is successfully fabricated with firstly demonstrated the passively Q-switched laser operation within a Yb-doped fiber laser cavity at 1066 nm. Few layered PtTe
2
is produced by uncomplicated and cost-efficient ultrasonic liquid exfoliation and follow by incorporating into polyvinyl alcohol (PVA) polymer to form a PtTe
2
-PVA composite thin film saturable absorber. The highest achieved single pulse energy is 74.0 nJ corresponding to pulse duration, repetition rate and average output power of 5.2 μs, 33.5 kHz and 2.48 mW, respectively. This work has further exploited the immeasurable utilization potential of the air stable and broadband group 10 TMDs for ultrafast photonic applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
