Preserved Time-reversal Symmetry Research Articles

Topology classification in bi-anisotropic topological photonic crystals via the Wilson loop approach [Invited

Topological photonic crystals have attracted tremendous attention due to their promise of robust optical properties and great potential for applications in on-chip devices. Numerous successful experimental demonstrations have shown or proved their topological properties, however, many of them turn out to have a nature of fragile topological phases. Here, using theoretical methods of fragile topology, we analyze two cases of topological photonic crystals with preserved time reversal symmetry, which utilize (1), the intrinsic duality and bi-anisotropy, and (2), accidental duality and structural bi-anisotropy respectively to induce their topological order. Our results show that the former case belongs to a Wannier-obstructed type of topological phase, indicating strong topological protection in their edge states. However, the latter meta-waveguide designs with structural bi-anisotropy widely implemented in experiments are Wannierizable, implying the fragile properties of their topology and gapped edge spectra. Our results provide new insights into the topological properties of photonic crystals as well as other bosonic systems with time-reversal symmetry.

Probing the superconducting pairing of the La4Be33Pt16 alloy via muon-spin spectroscopy

We report a study of the superconducting pairing of the noncentrosymmetric La4Be33Pt16 alloy using muon-spin rotation and relaxation (µSR) technique. Below K, La4Be33Pt16 exhibits bulk superconductivity (SC), here characterized by heat-capacity and magnetic-susceptibility measurements. The temperature dependence of the superfluid density , extracted from the transverse-field µSR measurements, reveals a nodeless SC in La4Be33Pt16. The best fit of using an s-wave model yields a magnetic penetration depth nm and a superconducting gap meV at zero Kelvin. The single-gapped superconducting state is further evidenced by the temperature-dependent electronic specific heat and the linear field-dependent electronic specific-heat coefficient . The zero-field µSR spectra collected in the normal- and superconducting states of La4Be33Pt16 are almost identical, confirming the absence of an additional field-related relaxation and, thus, of spontaneous magnetic fields below Tc . The nodeless SC combined with a preserved time-reversal symmetry in the superconducting state proves that the spin-singlet pairing is dominant in La4Be33Pt16. This material represents yet another example of a complex system showing only a conventional behavior, in spite of a noncentrosymmetric structure and a sizeable spin–orbit coupling.

Fully gapped superconductivity and topological aspects of the noncentrosymmetric superconductor TaReSi

We report a study of the noncentrosymmetric TaReSi superconductor by means of the muon-spin rotation and relaxation $(\ensuremath{\mu}\mathrm{SR})$ technique, complemented by electronic band-structure calculations. Its superconductivity, with ${T}_{c}=5.5\phantom{\rule{0.28em}{0ex}}\text{K}$ and upper critical field ${\ensuremath{\mu}}_{0}{H}_{\mathrm{c}2}(0)\ensuremath{\sim}3.4\phantom{\rule{0.28em}{0ex}}\text{T}$, was characterized via electrical-resistivity and magnetic-susceptibility measurements. The temperature-dependent superfluid density, obtained from transverse-field $\ensuremath{\mu}\mathrm{SR}$, suggests a fully gapped superconducting state in TaReSi, with an energy gap ${\mathrm{\ensuremath{\Delta}}}_{0}=0.79\phantom{\rule{0.28em}{0ex}}\text{meV}$ and a magnetic penetration depth ${\ensuremath{\lambda}}_{0}=562\phantom{\rule{0.28em}{0ex}}\text{nm}$. The absence of a spontaneous magnetization below ${T}_{c}$, as confirmed by zero-field $\ensuremath{\mu}\mathrm{SR}$, indicates a preserved time-reversal symmetry in the superconducting state. The density of states near the Fermi level is dominated by the Ta- and Re-$5d$ orbitals, which account for the relatively large band splitting due to the antisymmetric spin-orbit coupling. In its normal state, TaReSi behaves as a three-dimensional Kramers nodal-line semimetal, characterized by an hourglass-shaped dispersion protected by glide reflection. By combining nontrivial electronic bands with intrinsic superconductivity, TaReSi is a promising material for investigating the topological aspects of noncentrosymmetric superconductors.

Time reversal invariant single-gap superconductivity with upper critical field larger than the Pauli limit in NbIr2B2

Recently, compounds with noncentrosymmetric crystal structure have attracted much attention for providing a rich playground in search for unconventional superconductivity. NbIr$_2$B$_2$ is a new member to this class of materials harboring superconductivity below $T_{\rm c} = 7.3(2)$~K and very high upper critical field that exceeds Pauli limit. Here we report on muon spin rotation ($\mu$SR) experiments probing the temperature and field dependence of effective magnetic penetration depth in this compound. Our transverse-field -$\mu$SR results suggest a fully gaped $s$-wave superconductvity. Further, the estimated high value of upper critical field is also supplemented by high field transport measurements. Remarkably, the ratio $T_{\rm c}$/$\lambda^{-2}(0)$ obtained for NbIr$_2$B$_2$ ($\sim$2) is comparable to those of unconventional superconductors. Zero-field $\mu$SR data reveals no significant change in the muon spin relaxation rate above and below $T_{\rm c}$, evincing that time-reversal symmetry is preserved in the superconducting state. The presented results will stimulate theoretical investigations to obtain a microscopic understanding of the origin of superconductivity with preserved time reversal symmetry in this unique noncentrosymmetric system.

Fully gapped superconducting state in interstitial-carbon-doped Zr5Pt3

We report a comprehensive study of the ${\mathrm{Zr}}_{5}{\mathrm{Pt}}_{3}{\mathrm{C}}_{x}$ superconductors, with interstitial carbon between 0 and 0.3. At a macroscopic level, their superconductivity, with ${T}_{c}$ ranging from 4.5 to 6.3 K, was investigated via electrical-resistivity, magnetic-susceptibility, and specific-heat measurements. The upper critical fields ${\ensuremath{\mu}}_{0}{H}_{\mathrm{c}2}\ensuremath{\sim}7$ T were determined mostly from measurements of the electrical resistivity in applied magnetic field. The microscopic electronic properties were investigated by means of muon-spin rotation and relaxation ($\ensuremath{\mu}\mathrm{SR}$) and nuclear magnetic resonance (NMR) techniques. In the normal state, NMR relaxation data indicate an almost ideal metallic behavior, confirmed by band-structure calculations, which suggest a relatively high electronic density of states at the Fermi level, dominated by the Zr $4d$ orbitals. The low-temperature superfluid density, obtained via transverse-field $\ensuremath{\mu}\mathrm{SR}$, suggests a fully gapped superconducting state in ${\mathrm{Zr}}_{5}{\mathrm{Pt}}_{3}$ and ${\mathrm{Zr}}_{5}{\mathrm{Pt}}_{3}{\mathrm{C}}_{0.3}$, with zero-temperature gap ${\mathrm{\ensuremath{\Delta}}}_{0}=1.20$ and 0.60 meV and magnetic penetration depth ${\ensuremath{\lambda}}_{0}$ = 333 and 493 nm, respectively. The exponential dependence of the NMR relaxation rates below ${T}_{c}$ further supports nodeless superconductivity. The absence of spontaneous magnetic fields below the onset of superconductivity, as determined from zero-field $\ensuremath{\mu}\mathrm{SR}$ measurements, confirms the preserved time-reversal symmetry in the superconducting state of ${\mathrm{Zr}}_{5}{\mathrm{Pt}}_{3}{\mathrm{C}}_{x}$. In contrast to a previous study, our $\ensuremath{\mu}\mathrm{SR}$ and NMR results suggest conventional superconductivity in the ${\mathrm{Zr}}_{5}{\mathrm{Pt}}_{3}{\mathrm{C}}_{x}$ family, independent of the C content.

Nonlinear Hall response in the driving dynamics of ultracold atoms in optical lattices

We propose that a nonlinear Hall response can be observed in Bloch oscillations of ultracold atoms in optical lattices under the condition of preserved time-reversal symmetry. In the short-time limit of Bloch oscillations driven by a direct current (dc) field, the nonlinear Hall current dominates, being a second-order response to the external field strength. The associated Berry curvature dipole, which is a second-order nonlinear coefficient of the driving field, can be obtained from the oscillation of atoms. In an alternating current (ac) driving field, the nonlinear Hall response has a double frequency of the driving force in the case of time-reversal symmetry.

Quantum Spin Hall Phases in Graphene and the Atomically Thin Transition Metal Dichalcogenide Family

AbstractThe quantum‐spin‐Hall (QSH) phase with helical edge spin states, in which opposite‐moment electron spins counter‐propagate within a topologically preserved time reversal symmetry, is attracting considerable attention. The helical edge spin currents allow zero‐emission energy spintronic‐devices with small error rates by modulating with external bias voltages. Recently, QSH phases and possible 2D topological insulating states have been reported in various atomically thin layers (such as graphene and the transition metal dichalcogenide family). Particularly, (twisted) bi‐layer graphene on heavy substrates is becoming a novel candidate for robust QSH phases (including Chern insulating phases), nevertheless, graphene itself lacks spin‐orbit coupling owing to the light carbon atoms. Here, research of QSH phases focusing on graphene is reviewed, particularly for using heavy adatom decoration and heavy substrates. They will open the door to next‐generation spintronic architectures.

Eigenfunction non-orthogonality factors and the shape of CPA-like dips in a single-channel reflection from lossy chaotic cavities

Motivated by the phenomenon of coherent perfect absorption, we study the shape of the deepest dips in the frequency-dependent single-channel reflection of waves from a cavity with spatially uniform losses. We show that it is largely determined by non-orthogonality factors O nn of the eigenmodes associated with the non-selfadjoint effective Hamiltonian. For cavities supporting chaotic ray dynamics we then use random matrix theory to derive, fully non-perturbatively, the explicit distribution of the non-orthogonality factors for systems with both broken and preserved time reversal symmetry. The results imply that O nn are heavy-tail distributed. As a by-product, we derive an explicit non-perturbative expression for the resonance density in a single-channel chaotic systems in a much simpler form than available in the literature.

Evidence of fully gapped superconductivity in NbReSi: A combined μSR and NMR study

We report a comprehensive study of the noncentrosymmetric NbReSi superconductor by means of muon-spin rotation and relaxation ($\mu$SR) and nuclear magnetic resonance (NMR) techniques. NbReSi is a bulk superconductor with $T_c = 6.5$ K, characterized by a large upper critical field, which exceeds the Pauli limit. Both the superfluid density $\rho_\mathrm{sc}(T)$ (determined via transverse-field $\mu$SR) and the spin-lattice relaxation rate $T_1^{-1}(T)$ (determined via NMR) suggest a nodeless superconductivity (SC) in NbReSi. We also find signatures of multigap SC, here evidenced by the field-dependent muon-spin relaxation rate and the electronic specific-heat coefficient. The absence of spontaneous magnetic fields below $T_c$, as evinced from zero-field $\mu$SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of NbReSi. Finally, we discuss possible reasons for the unusually large upper critical field of NbReSi, most likely arising from its anisotropic crystal structure.

Multigap superconductivity in centrosymmetric and noncentrosymmetric rhenium-boron superconductors

We report a comprehensive study of the centrosymmetric Re$_3$B and noncentrosymmetric Re$_7$B$_3$ superconductors. At a macroscopic level, their bulk superconductivity (SC), with $T_c$ = 5.1 K (Re$_3$B) and 3.3 K (Re$_7$B$_3$), was characterized via electrical-resistivity, magnetization, and heat-capacity measurements, while their microscopic superconducting properties were investigated by means of muon-spin rotation/relaxation ($\mu$SR). In both Re$_3$B and Re$_7$B$_3$ the low-$T$ zero-field electronic specific heat and the superfluid density (determined via tranverse-field $\mu$SR) suggest a nodeless SC. Both compounds exhibit some features of multigap SC, as evidenced by temperature-dependent upper critical fields $H_\mathrm{c2}(T)$, as well as by electronic band-structure calculations. The absence of spontaneous magnetic fields below the onset of SC, as determined from zero-field $\mu$SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of both Re$_3$B and Re$_7$B$_3$. Our results suggest that a lack of inversion symmetry and the accompanying antisymmetric spin-orbit coupling effects are not essential for the occurrence of multigap SC in these rhenium-boron compounds.

Isotropic s -wave superconductivity in the noncentrosymmetric charge density wave superconductor SrPt2As2

${\mathrm{SrPt}}_{2}{\mathrm{As}}_{2}$ undergoes a structural transition around 470 K (from a high-temperature tetragonal to a low-temperature orthorhombic phase) accompanied by a charge density wave transition and followed by a superconducting transition at much lower temperature (5 K). The superconducting gap symmetry of this noncentrosymmetric compound was investigated in detail by means of muon-spin rotation or relaxation $(\ensuremath{\mu}\mathrm{SR})$ experiments in transverse-field (TF) configuration. The temperature-dependent magnetic penetration depth obtained from the $\mathrm{TF}\text{\ensuremath{-}}\ensuremath{\mu}\mathrm{SR}$ spectra suggests an isotropic $s$-wave-type superconducting gap. No observable differences are seen in the asymmetry time spectra collected in zero field above and below the superconducting transition temperature ${T}_{c}$. This strongly suggests the absence of spontaneous magnetic fields in the superconducting state, hence pointing to a preserved time-reversal symmetry below ${T}_{c}$.

Edge switch transformation in microwave networks.

We investigated the spectra of resonances of four-vertex microwave networks simulating both quantum graphs with preserved and with partially violated time-reversal invariance before and after an edge switch operation. We show experimentally that under the edge switch operation, the spectra of the microwave networks with preserved time-reversal symmetry are level-1 interlaced, i.e., ν_{n-r}≤ν[over ̃]_{n}≤ν_{n+r}, where r=1, in agreement with the recent theoretical predictions of Aizenman etal. [M. Aizenman, H. Schanz, U. Smilansky, and S. Warzel, Acta Phys. Pol. A 132, 1699 (2017)ATPLB60587-424610.12693/APhysPolA.132.1699]. Here, we denote by {ν_{n}}_{n=1}^{∞} and {ν[over ̃]_{n}}_{n=1}^{∞} the spectra of microwave networks before and after the edge switch transformation. We demonstrate that the experimental distribution P(ΔN) of the spectral shift ΔN is close to the theoretical one. Furthermore, we show experimentally that in the case of the four-vertex networks with partially violated time-reversal symmetry, the spectra are level-1 interlaced. Our experimental results are supplemented by the numerical calculations performed for quantum graphs with violated time-reversal symmetry. In this case, the edge switch transformation also leads to the spectra which are level-1 interlaced. Moreover, we demonstrate that for microwave networks simulating graphs with violated time-reversal symmetry, the experimental distribution P(ΔN) of the spectral shift ΔN agrees, within the experimental uncertainty, with the numerical one.

Enhanced Tc and multiband superconductivity in the fully-gapped ReBe22 superconductor

In search of the origin of superconductivity (SC) in diluted rhenium superconductors and their significantly enhanced Tc compared to pure Be (0.026 K), we investigated the intermetallic ReBe22 compound, mostly by means of muon-spin rotation/relaxation (μSR). At a macroscopic level, its bulk SC (with Tc = 9.4 K) was studied via electrical resistivity, magnetization, and heat-capacity measurements. The superfluid density, as determined from transverse-field μSR and electronic specific-heat measurements, suggest that ReBe22 is a fully-gapped superconductor with some multigap features. The larger gap value, , with a weight of almost 90%, is slightly higher than that expected from the BCS theory in the weak-coupling case. The multigap feature, rather unusual for an almost elemental superconductor, is further supported by the field-dependent specific-heat coefficient, the temperature dependence of the upper critical field, as well as by electronic band-structure calculations. The absence of spontaneous magnetic fields below Tc, as determined from zero-field μSR measurements, indicates a preserved time-reversal symmetry in the superconducting state of ReBe22. In general, we find that a dramatic increase in the density of states at the Fermi level and an increase in the electron–phonon coupling strength, both contribute to the highly enhanced Tc value of ReBe22.

Nodeless superconductivity and preserved time-reversal symmetry in the noncentrosymmetric Mo3P superconductor

We report a comprehensive study of the noncentrosymmetric superconductor Mo$_3$P. Its bulk superconductivity, with $T_c = 5.5$ K, was characterized via electrical resistivity, magnetization, and heat-capacity measurements, while its microscopic electronic properties were investigated by means of muon-spin rotation/relaxation ($\mu$SR) and nuclear magnetic resonance (NMR) techniques. In the normal state, NMR relaxation data indicate an almost ideal metallic behavior, confirmed by band-structure calculations, which suggest a relatively high electron density of states, dominated by the Mo $4d$-orbitals. The low-temperature superfluid density, determined via transverse-field $\mu$SR and electronic specific heat, suggest a fully-gapped superconducting state in Mo$_3$P, with $\Delta_0= 0.83$ meV, the same as the BCS gap value in the weak-coupling case, and a zero-temperature magnetic penetration depth $\lambda_0 = 126$ nm. The absence of spontaneous magnetic fields below the onset of superconductivity, as determined from zero-field $\mu$SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of Mo$_3$P and, hence, spin-singlet pairing.

Superconductivity in Ru0.55Rh0.45P and Ru0.75Rh0.25As probed by muon spin relaxation and rotation measurements

Superconductivity in the pseudo-binary pnictides Ru0.55Rh0.45P and Ru0.75Rh0.25As is probed by muon spin relaxation and rotation (muSR) measurements in conjuction with magnetic susceptibility, heat capacity and electrical resistivity measurements. Powder x-ray diffraction confirmed the MnP-type orthorhombic structure (space group Pnma) and showed a nearly single phase nature with small impurity phase(s) of about 5% for both the samples. The occurence of bulk superconductivity is confirmed with Tc = 3.7 K for Ru0.55Rh0.45P and T = 1.6 K for Ru0.75Rh0.25As. The superconducting state electronic heat capacity data reveal weak-coupling single-band isotropic s-wave gap BCS superconductivity. Various normal and superconducting state parameters are determined which reveal a weak-coupling electron-phonon driven type-II dirty-limit superconductivity for both the compounds. The upper critical field shows a linear temperature dependence down to the lowest measured temperatures which is quite unusual for a single-band superconductor. The muSR data confirm the conventional type-II behavior, and show evidence for a single-band s-wave singlet pairing superconductivity with a preserved time reversal symmetry for both the compounds.

Nodeless superconductivity in the noncentrosymmetric Mo3Rh2N superconductor: A μSR study

The noncentrosymmetric superconductor Mo$_3$Rh$_2$N, with $T_c = 4.6$ K, adopts a $\beta$-Mn-type structure (space group $P$4$_1$32), similar to that of Mo$_3$Al$_2$C. Its bulk superconductivity was characterized by magnetization and heat-capacity measurements, while its microscopic electronic properties were investigated by means of muon-spin rotation and relaxation ($\mu$SR). The low-temperature superfluid density, measured via transverse-field (TF)-$\mu$SR, evidences a fully-gapped superconducting state with $\Delta_0 = 1.73 k_\mathrm{B}T_c$, very close to 1.76 $k_\mathrm{B}T_c$ - the BCS gap value for the weak coupling case, and a magnetic penetration depth $\lambda_0 = 586$ nm. The absence of spontaneous magnetic fields below the onset of superconductivity, as determined by zero-field (ZF)-$\mu$SR measurements, hints at a preserved time-reversal symmetry in the superconducting state. Both TF-and ZF-$\mu$SR results evidence a spin-singlet pairing in Mo$_3$Rh$_2$N.

Acoustic topological insulators

The recent discovery of topological states in condensed matter physics has spawned a quest for similar effects in classical physics. Topological insulators are bulk insulators supporting bandgap crossing, chiral edge states that are immune to backscattering caused by defects or disorder. Here, we present the acoustic equivalent of topological insulators, obtaining the analog of the Quantum Hall Effect (QHE) and the Quantum Spin-Hall Effect (QSHE) in acoustic metamaterials with, respectively, broken or preserved time-reversal symmetry. We demonstrate how our recent results in the field of non-reciprocal acoustics [cf. Science 343, 516 (2013); Ac. Today. 11, 14 (2015)] can be used to induce an acoustic version of the QHE in active metamaterials with broken time-reversal symmetry. We also put forward resonant and non-resonant schemes to emulate the Kane-Mele Hamiltonian in completely passive acoustic metamaterials, obtaining the acoustic analog of the QSHE. Our work reveals that topological acoustic metamaterials enable fundamentally new ways of manipulating sound, including one-way, chiral propagation of acoustic waves over broad bandwidth and topological protection against geometry imperfections, impedance mismatches, crystal defects, and local disorder.

Quantum non-Abelian hydrodynamics: Anyonic or spin–orbital entangled liquids, nonunitarity of scattering matrix and charge fractionalization

In this article, we develop an exact (nonadiabatic, nonperturbative) density matrix scattering theory for a two component quantum liquid which interacts or scatters off from a generic spin-dependent quantum potential. The generic spin dependent quantum potential [Eq. (1)] is a matrix potential, hence, adiabaticity criterion is ill-defined. Therefore the full matrix potential should be treated nonadiabatically. We succeed in doing so using the notion of vectorial matrices which allows us to obtain an exact analytical expression for the scattered density matrix (SDM), ϱsc[Eq. (30)]. We find that the number or charge density in scattered fluid, Tr (ϱsc), expressions in Eqs. (32) depends on nontrivial quantum interference coefficients, [Formula: see text], which arises due to quantum interference between spin-independent and spin-dependent scattering amplitudes and among spin-dependent scattering amplitudes. Further it is shown that Tr (ϱsc) can be expressed in a compact form [Eq. (39)] where the effect of quantum interference coefficients can be included using a vector Qαβ, which allows us to define a vector order parameterQ. Since the number density is obtained using an exact scattered density matrix, therefore, we do not need to prove that Q is non-zero. However, for sake of completeness, we make detailed mathematical analysis for the conditions under which the vector order parameterQ would be zero or nonzero.We find that in presence of spin-dependent interaction the vector order parameterQ is necessarily nonzero and is related to the commutator and anti-commutator of scattering matrix S with its dagger S†[Eq. (78)]. It is further shown that Q≠0, implies four physically equivalent conditions,i.e., spin-orbital entanglement is nonzero, non-Abelian scattering phase, i.e., matrices, scattering matrix is nonunitary and the broken time reversal symmetry for SDM. This also implies that quasi particle excitation are anyonic in nature, hence, charge fractionalization is a natural consequence. This aspect has also been discussed from the perspective of number or charge density conservation, which implies i.e., Tr (ϱ}sc) = Tr (ϱin). On the other hand Q = 0 turns out to be a mathematically forced unphysical solution in presence of spin-dependent potential or scattering which is equivalent to Abelian hydrodynamics, unitary scattering matrix, absence of spin-space entanglement and preserved time reversal symmetry. We have formulated the theory using mesoscopic language, specifically, we have considered two terminal systems connected to spin-dependent scattering region, which is equivalent to having two potential wells separated by a generic spin-dependent potential barrier. The formulation using mesoscopic language is practically useful because it leads directly to the measured quantities such as conductance and spin-polarization density in the leads, however, the presented formulation is not limited to the mesoscopic system only, its generality has been stressed at various places in this article.

Topological metallic phases in spin–orbit coupled bilayer systems

We investigate the influence of different spin–orbit couplings on topological phase transitions in the bilayer Kane–Mele model. We find that the competition between intrinsic spin–orbit coupling and Rashba spin–orbit coupling can lead to two dimensional topological metallic states with nontrivial topology. Such phases, although having a metallic bulk, still possess edge states with well defined topological invariants. Specifically, we show that with preserved time reversal symmetry the system can exhibit a -metallic phase with spin helical edge states and a nontrivial invariant. When time reversal symmetry is broken, a Chern metallic phase could appear with chiral edge states and a nontrivial Chern invariant.

Physical properties of noncentrosymmetric superconductorLaIrSi3: AμSR study

The results of heat capacity C_p(T, H) and electrical resistivity \rho(T,H) measurements down to 0.35 K as well as muon spin relaxation and rotation (\muSR) measurements on a noncentrosymmetric superconductor LaIrSi3 are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal BaNiSn3-type structure (space group I4\,mm) of LaIrSi3. The bulk superconductivity is observed below T_c = 0.72(1) K. The intrinsic \Delta C_e/\gamma_n T_c = 1.09(3) is significantly smaller than the BCS value of 1.43, and this reduction is accounted by the \alpha-model of BCS superconductivity. The analysis of the superconducting state C_e(T) data by the single-band \alpha-model indicates a moderately anisotropic order parameter with the s-wave gap \Delta(0)/k_B T_c = 1.54(2) which is lower than the BCS value of 1.764. Our estimates of various normal and superconducting state parameters indicate a weakly coupled electron-phonon driven type-I s-wave superconductivity in LaIrSi3. The \muSR results also confirm the conventional type-I superconductivity in LaIrSi3 with a preserved time reversal symmetry and hence a singlet pairing superconducting ground state.