Spintronic Structures Research Articles

Anomalous Nernst Effect-Based Near-Field Imaging of Magnetic Nanostructures.

The anomalous Nernst effect (ANE) gives rise to an electrical response transverse to magnetization and an applied temperature gradient in a magnetic metal. A nanoscale temperature gradient can be generated by the use of a laser beam applied to the apex of an atomic force microscope tip, thereby allowing for spatially resolved ANE measurements beyond the optical diffraction limit. Such a method has been previously used to map in-plane magnetized magnetic textures. However, the spatial distribution of the out-of-plane temperature gradient, which is needed to fully interpret such ANE-based imaging, was not studied. We therefore use a well-known magnetic texture, a magnetic vortex core, to demonstrate the reliability of the ANE method for imaging of magnetic domains with nanoscale resolution. Moreover, since the ANE signal is directly proportional to the temperature gradient, we can also consider the inverse problem and deduce information about the nanoscale temperature distribution. Our results together with finite element modeling indicate that besides the out-of-plane temperature gradients there are even larger in-plane temperature gradients. Thus, we extend the ANE imaging to study the out-of-plane magnetization in a racetrack nanowire by detecting the ANE signal generated by in-plane temperature gradients. In all cases, a spatial resolution of ≈70 nm is obtained. These results are significant for the rapidly growing field of thermoelectric imaging of antiferromagnetic spintronic device structures.

Metal–Organic Frameworks with Axial Cobalt–Oxygen Coordination Modulate Polysulfide Redox for Lithium–Sulfur Batteries

AbstractAlthough the ultrahigh theoretical energy density and cost‐effectiveness, lithium–sulfur (Li‐S) batteries suffer from sluggish conversion kinetics and the shuttling effect of soluble lithium polysulfides (LiPSs). Herein, conductive hexagonal cobalt‐organic framework (Co‐HTP) nanosheets are anchored in situ on carboxyl graphene (CG) substrates and serve as host catalysts to modulate the polysulfide redox. Substantial characterizations identify that the local coordination environment of the quadrilateral Co–N4 units transforms into an asymmetric penta‐coordinated O–Co–N4 with axial Co─O coordination, which triggers spin polarization and remarkable electron delocalization of Co 3d orbital. The higher spin state and lower local electron density of the O–Co–N4 sites induce more active electronic states in Co‐HTP/CG and facilitate orbital hybridization with polysulfides to form more stable bond orders. Such optimized electronic structure significantly accelerates redox kinetics and enhances the adsorption strength of polysulfides. These merit the lithium–sulfur battery based on Co‐HTP/CG with a high reversible capacity, impressive rate capability, and prolonged cycling performance over 500 cycles. This work will enrich the design philosophy of modulating the spintronic structure of electrocatalysts for advanced Li–S batteries and beyond.

Spintronic device in SWCNT-FET configuration based on chromium oxides thin films consisting of half-metallic ferromagnetic CrO2

Spintronic device architectures consisting of ferromagnetic chromium oxide electrodes in single-walled carbon nanotubes field effect transistor (SWCNT-FET) configuration have been fabricated to act as strategic building blocks for next generation super-compact high-speed nanoelectronic devices for logic and memory operations. Stable thin films of chromium oxides consisting of half-metallic ferromagnetic chromium-di-oxide (CrO2) were pulsed laser deposited (PLD) over lattice-matched rutile-type-tetragonal intermediate TiO2 thin layers over thermally oxidized Si substrates for engineering of the spintronic device structure. Focused ion beam (FIB) milling was applied to the ferromagnetic chromium oxide thin films for patterning of the source (S) and (D) electrodes. Typical electrical characteristics derived by lnρ vs. T−1/2 plots confirmed spin-dependent transport (SDT) as the dominant mechanism of electrical conduction upto temperatures of ∼280 K along with negative magnetoresistance (MR) of ∼30 % at 278 K. Electrical characteristics (output and transfer) of the spintronic device structure were drawn under application of magnetic field (H) in out-of-plane geometry at the temperatures of 5.6 K, 250 K & 300 K. Drain current (Id) is demonstrated to be controlled effectively as a function of gate bias (Vg) for different fixed Vd-biases at all the device operating temperatures. Change in %MR as a function of gate voltage (Vg) was acquired at T = 250 &T = 300 K that displayed higher %MR change under out-of-plane geometry of applied field of 0.75 T of the spintronic device operation.

First-Principles investigations into electronic, magnetic, elastic, and optical phenomena in SmCrO3: Towards spintronic and magnetic storage applications

Using a thorough DFT analysis, this work investigates the electronic, magnetic, elastic, and optical phenomena in the cubic and orthorhombic phases of SmCrO3. The study explores the distinct qualities of both phases, such as their electronic features, magnetic behaviors, and elastic responses, using the GGA-PBE and mBJ-GGA-PBE methodologies. The study highlights the potential of SmCrO3 cubic and orthorhombic structures in spintronics and magnetic device applications by confirming their half-metallic nature. A deeper understanding of the electronic structure and magnetic stability of the materials results from the intricate interplay of spin effects and thorough investigation of magnetic interactions.

Chemical Doping of Organic and Coordination Polymers for Thermoelectric and Spintronic Applications: A Theoretical Understanding.

ConspectusThe controlled doping of organic semiconductors (OSCs) is crucial not only for improving the performance of electronic and optoelectronic devices but also for enabling efficient thermoelectric conversion and spintronic applications. The mechanism of doping for OSCs is fundamentally different from that of their inorganic counterparts. In particular, the interplay between dopants and host materials is complicated considering the low dielectric constant, strong lattice-charge interaction, and flexible nature of materials. Recent experimental breakthroughs in the molecular design of dopants and the precise doping with high spatial resolution call for more profound understandings as to how the dopant interacts with the charge introduced to OSCs and how the admixture of dopants alters the electronic properties of host materials before one can exploit controllable doping to realize desired functionalities.By employing state-of-the-art computational tools, we revealed the effects of doping in representative and emerging organic and coordination polymers aiming toward thermoelectric and spintronic applications. We showed that dopants and hosts should be taken as an integrated system, and the type of charge-transfer interaction between them is the key for spin polarization. First, we found doping-induced modifications to the electronic band in a potassium-doped coordination polymer, an n-type thermoelectric material. The charge localization due to the Coulomb interaction between the completely ionized dopant and the injected charge on the polymer backbone and also the polaron band formation at low doping levels are responsible for the nonmonotonic temperature dependence of the conductivity and Seebeck coefficient observed in recent experiments. The mechanistic insights gained from these results have provided important guidelines on how to control the doping level and working temperature to achieve a high thermoelectric conversion efficiency. Next, we demonstrated that the ionized dopants scatter charge carriers via screened Coulomb interactions, and it may become a dominant scattering mechanism in doped polymers. After incorporating the ionized dopant scattering mechanism in PEDOT:Tos, a p-type thermoelectric polymer, we were able to reproduce the measured Seebeck coefficient-electrical conductivity relationship spanning a wide range of doping levels, highlighting the importance of ionized dopant scattering in charge transport.In the two cases described above, charge injection is enabled by integral charge transfer between the dopant and host polymers. In a third example, we showed that a novel type of stacked two-dimensional polymer, conjugated covalent organic frameworks (COFs) with closed-shell electronic structures, can be spin polarized by iodine doping via fractional charge transfer even at high doping levels. We then manifested that magnetization can be attained in nonmagnetic materials lacking metal d electrons and further designed two new COFs with tunable spintronic structure and magnetic interactions after the iodine doping. These findings have suggested a practical route to enable spin polarization in nonradical materials by chemical doping via orbital hybridization, which holds great promise for flexible spintronic applications.

Crystalline restacking of 2D-materials from their nanosheets suspensions.

We report here the highly ordered restacking of the layered phosphatoantimonic dielectric materials H3(1-x)M3xSb3P2O14, (where M = Li, Na, K, Rb, Cs and 0 ≤ x ≤ 1), from their nanosheets dispersed in colloidal suspension, induced by a simple pH change using alkaline bases. H3Sb3P2O14 aqueous suspensions are some of the rare examples of colloidal suspensions based on 2D materials exhibiting a lamellar liquid crystalline phase. Because the lamellar period can reach several hundred nanometers, the suspensions show vivid structural colors and because these colors are sensitive to various chemicals, the suspensions can be used as sensors. The structures of the lamellar liquid crystalline phase and the restacked phase have been studied by X-ray scattering (small and wide angle), which has followed the dependence of the lamellar/restacked phase equilibrium on the cation exchange rate, x. The X-ray diffraction pattern of the restacked phase is almost identical to that of the M3Sb3P2O14 crystalline phase, showing that the restacking is highly accurate and avoids the turbostratic disorder of the nanosheets classically observed in nanosheet stacking of other 2D materials. Strikingly, the restacking process exhibits features highly reminiscent of a first-order phase transition, with the existence of a phase coexistence region where both ∼1 nm (interlayer spacing of the restacked phase) and ∼120 nm lamellar periods can be observed simultaneously. Furthermore, this first-order phase transition is well described theoretically by incorporating a Lennard-Jones-type lamellar interaction potential into an entropy-based statistical physics model of the lamellar phase of nanosheets. Our work shows that the precise cation exchange produced at room temperature by a classical neutralization reaction using alkaline bases leads to a crystal-like restacking of the exfoliated free Sb3P2O143- nanosheets from suspension, avoiding the turbostratic disorder typical of van der Waals 2D materials, which is detrimental to the controlled deposition of nanosheets into complex integrated electronic, spintronic, photonic or quantum structures.

Impact of various spintronic antenna structures driven by a 795 nm pump beam to terahertz (THz) wave generation

We compare THz emission properties of rectangular, circular, and diabolo spintronic antennas composed of 2 nm Fe and 3 nm Pt layers on MgO substrates. Although the rectangular antenna generated the highest amplitude (∼1.8× improvement), the radiation spectra showed no significant difference. To fully check the effect of antennas, we fabricated diabolo and rectangular antennas with 200 nm Pt layer at the displacement current direction. We observed a 4.2× amplitude improvement using the rectangular antenna and a shift in the bandwidth as well as the peak frequency. These results suggest that spintronic antennas can be designed to be well-suited for specific applications.

Ultrafast light-induced THz switching in exchange-biased Fe/Pt spintronic heterostructure

The ultrafast optical control of magnetization in spintronic structures enables one to access to the high-speed information processing, approaching the realm of terahertz (THz). Femtosecond visible/near-infrared laser-driven ferromagnetic/nonmagnetic metallic spintronic heterostructures-based THz emitters combine the aspects from the ultrafast photo-induced dynamics and spin-charge inter-conversion mechanisms through the generation of THz electromagnetic pulses. In this Letter, we demonstrate photoexcitation density-dependent induced exchange-bias tunability and THz switching in an annealed Fe/Pt thin-film heterostructure, which otherwise is a widely used conventional spintronic THz emitter. By combining the exchange-bias effect along with THz emission, the photo-induced THz switching is observed without any applied magnetic field. These results pave the way for an all-optical ultrafast mechanism to exchange-bias tuning in spintronic devices for high-density storage, read/write magnetic memory applications.

Spintronic terahertz emitters exploiting uniaxial magnetic anisotropy for field-free emission and polarization control

We explore the terahertz (THz) emission from CoFeB/Pt spintronic structures in the below-magnetic-saturation regime and reveal an orientation dependence in the emission, arising from in-plane uniaxial magnetic anisotropy (UMA) in the ferromagnetic layer. Maximizing the UMA during the film deposition process and aligning the applied magnetic field with the easy axis of the structure allow the THz emission to reach saturation under weaker applied fields. In addition, the THz emission amplitude remains at saturation levels when the applied field is removed. The development of CoFeB/Pt spintronic structures that can emit broadband THz pulses without the need for an applied magnetic field is beneficial to THz magneto-optical spectroscopy and facilitates the production of large-area spintronic emitters. Furthermore, by aligning the applied field along the hard axis of the structure, the linear polarization plane of the emitted THz radiation can be manipulated by changing the magnitude of the applied field. We, therefore, demonstrate THz polarization control without the need for mechanical rotation of external magnets.

Spin-Orbit Coupling and Spin-Polarized Electronic Structures of Janus Vanadium-Dichalcogenide Monolayers: First-Principles Calculations.

Phonon and spintronic structures of monolayered Janus vanadium-dichalcogenide compounds are calculated by the first-principles schemes of pseudopotential plane-wave based on spin-density functional theory, to study dynamic structural stability and electronic spin-splitting due to spin-orbit coupling (SOC) and spin polarization. Geometry optimizations and phonon-dispersion spectra demonstrate that vanadium-dichalcogenide monolayers possess a high enough cohesive energy, while VSTe and VTe2 monolayers specially possess a relatively higher in-plane elastic coefficient and represent a dynamically stable structure without any virtual frequency of atomic vibration modes. Atomic population charges and electron density differences demonstrate that V–Te covalent bonds cause a high electrostatic potential gradient perpendicular to layer-plane internal VSTe and VSeTe monolayers. The spin polarization of vanadium 3d-orbital component causes a pronounced energetic spin-splitting of electronic-states near the Fermi level, leading to a semimetal band-structure and increasing optoelectronic band-gap. Rashba spin-splitting around G point in Brillouin zone can be specifically introduced into Janus VSeTe monolayer by strong chalcogen SOC together with a high intrinsic electric field (potential gradient) perpendicular to layer-plane. The vertical splitting of band-edge at K point can be enhanced by a stronger SOC of the chalcogen elements with larger atom numbers for constituting Janus V-dichalcogenide monolayers. The collinear spin-polarization causes the band-edge spin-splitting across Fermi level and leads to a ferrimagnetic order in layer-plane between V and chalcogen cations with higher α and β spin densities, respectively, which accounts for a large net spin as manifested more apparently in VSeTe monolayer. In a conclusion for Janus vanadium-dichalcogenide monolayers, the significant Rashba splitting with an enhanced K-point vertical splitting can be effectively introduced by a strong SOC in VSeTe monolayer, which simultaneously represents the largest net spin of 1.64 (ћ/2) per unit cell. The present study provides a normative scheme for first-principles electronic structure calculations of spintronic low-dimensional materials, and suggests a prospective extension of two-dimensional compound materials applied to spintronics.

First-principles computational exploration of ferromagnetism in monolayer GaS via substitutional doping

Using first-principles calculations, functionalization of the monolayer-GaS crystal structure through N or Cr-doping at all possible lattice sites has been investigated. Our results show that pristine monolayer-GaS is an indirect-bandgap, non-magnetic semiconductor. The bandgap can be tuned and a magnetic moment (MM) can be induced by the introduction of N or Cr atomic anion/cation doping in monolayer GaS. For instance, the intrinsic character of monolayer GaS can be changed by substitution of N for the S-site to p-type, while substitution of Cr at the S-site or Ga-site induces half-metallicity at sufficiently high concentrations. The defect states are located in the electronic bandgap region of the GaS monolayer. These findings help to extend the application of monolayer-GaS structures in nano-electronics and spintronics. Since the S-sites at the surface are more easily accessible to doping in experiment, we chose the S-site for further investigations. Finally, we perform calculations with ferromagnetic (FM) and antiferromagnetic (AFM) alignment of the MMs at the dopants. For pairs of impurities of the same species at low concentrations we find Cr atoms to prefer the FM state, while N atoms prefer the AFM state, both for impurities on opposite surfaces of the GaS monolayer and for impurities sharing a common Ga neighbor sitting at the same surface. Extending our study to higher concentrations of Cr atoms, we find that clusters of four Cr atoms prefer AFM coupling, whereas the FM coupling is retained for Cr atoms at larger distance arranged on a honeycomb lattice. For the latter arrangement, we estimate the FM Curie temperature T C to be 241 K. We conclude that the Cr-doped monolayer-GaS crystal structure offers enhanced electronic and magnetic properties and is an appealing candidate for spintronic devices operating close to room temperature.

Observation of Coherent Spin Waves in a Three-Dimensional Artificial Spin Ice Structure

Harnessing high-frequency spin dynamics in three-dimensional (3D) nanostructures may lead to paradigm-shifting, next-generation devices including high density spintronics and neuromorphic systems. Despite remarkable progress in fabrication, the measurement and interpretation of spin dynamics in complex 3D structures remain exceptionally challenging. Here, we take a first step and measure coherent spin waves within a 3D artificial spin ice (ASI) structure using Brillouin light scattering. The 3D-ASI was fabricated by using a combination of two-photon lithography and thermal evaporation. Two spin-wave modes were observed in the experiment whose frequencies showed nearly monotonic variation with the applied field strength. Numerical simulations qualitatively reproduced the observed modes. The simulated mode profiles revealed the collective nature of the modes extending throughout the complex network of nanowires while showing spatial quantization with varying mode quantization numbers. The study shows a well-defined means to explore high-frequency spin dynamics in complex 3D spintronic and magnonic structures.

A Task-Schedulable Nonvolatile Spintronic Field-Programmable Gate Array

Despite the vast hardware resources available in field-programmable gate arrays (FPGAs), the implementation of very large and complex designs on these platforms is a challenging problem. One effective solution is to use task scheduling. In this method, the FPGA configuration is changed according to the required task. This requires access to external nonvolatile memory, which significantly reduces system performance. In this letter, the development of a nonvolatile spintronic FPGA structure with task-scheduling capability is described. By using the nonvolatile feature of the magnetic tunnel junction device, the structure can store two different configurations in a nonvolatile way, which eliminates the need for external memory access and significantly enhances system performance.

Ultrafast spin-currents and charge conversion at 3d-5d interfaces probed by time-domain terahertz spectroscopy

Spintronic structures are extensively investigated for their spin–orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-transition metal interfaces due to their inverse spin-Hall effect properties. In particular, the intrinsic inverse spin-Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques—ultrafast THz time-domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping measurements in the GHz regime in the steady state—to determine the role played by the material properties, resistivities, spin transmission at metallic interfaces, and spin-flip rates. These measurements show the correspondence between the THz time-domain spectroscopy and ferromagnetic spin-pumping for the different set of samples in term of the spin mixing conductance. The latter quantity is a critical parameter, determining the strength of the THz emission from spintronic interfaces. This is further supported by ab initio calculations, simulations, and analysis of the spin-diffusion and spin-relaxation of carriers within the multilayers in the time domain, permitting one to determine the main trends and the role of spin transmission at interfaces. This work illustrates that time-domain spectroscopy for spin-based THz emission is a powerful technique to probe spin-dynamics at active spintronic interfaces and to extract key material properties for spin-charge conversion.

Synthesis of Ferromagnetic Alloys Semiconductor–Ferromagnet in the CdAs2–MnAs System

Semiconductor–ferromagnet alloys in the CdAs2–MnAs system were synthesized in evacuated ampules. Differential thermal analysis (DTA), X-ray powder diffraction analysis, differential scanning calorimetry, and scanning electron microscopy showed that this system is eutectic (of the acicular type), and the coordinates of the eutectic are (6 ± 0.5 mol % MnAs, Tmelt = 614 ± 1°C). The liquidus lines constructed based on the thermal events of melting in DTA are 40–50°C higher than the lines constructed based on the thermal events of crystallization, which is due to the tendency of CdAs2 toward glass transition. The synthesized alloys are ferromagnetic with TC = 315 K, and the magnetization of them increases with increasing MnAs content. The alloys with nanoinclusions ≤40 nm of the ferromagnetic phase MnAs were produced by crystallization from melts at high cooling rates (≤100 deg/s). They have a higher Curie temperature of TC = 353 K and a negative magnetoresistance of ΔR = 2% at 300 K in a saturation magnetic field of 4500 Oe, which is of practical interest for creating magnetic granular spintronic structures.

Active photonic platforms for the mid-infrared to the THz regime using spintronic structures

Abstract Spintronics and Photonics constitute separately two disciplines of huge scientific and technological impact. Exploring their conceptual and practical overlap offers vast possibilities of research and a clear scope for the corresponding communities to merge and consider innovative ideas taking advantage of each other’s potentials. As an example, here we review the magnetic field modification of the optical response of photonic systems fabricated out of spintronic materials, or in which spintronic components are incorporated. This magnetic actuation is due to the Magneto Refractive Effect (MRE), which accounts for the change in the optical constants of a spintronic system due to the magnetic field induced modification of the electrical resistivity. Due to the direct implication of conduction electrons in this phenomenon, this change in the optical constants covers from the mid-infrared to the THz regime. After introducing the non-expert reader into the spintronic concepts relevant to this work, we then present the MRE exhibited by a variety of spintronic systems, and finally show the different applications of this property in the generation of active spintronic-photonic platforms.

Terahertz Time-Domain Spectroscopy

Time-Domain terahertz spectroscopy (THz TDS) has attracted attention from many scientific disciplines as it enables accessing the gap between electronic and optical techniques. One application is to probe spintronic dynamics in sub-picosecond time scale. Here, we discuss principles and technical aspects of a typical THz TDS setup. We also show an example of terahertz time-domain data obtained from a Co/Pt thin film calibrant, which is a well-studied spintronic structure emitting strong THz radiation. See video at https://youtu.be/X7vrvQcmy8c.

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

AbstractBismuth iron garnet Bi3Fe5O12 (BIG) is a multifunctional insulating oxide exhibiting remarkably the largest known Faraday rotation and linear magnetoelectric coupling. Enhancing the electrical conductivity in BIG while preserving its magnetic properties would further widen its range of potential applications in oxitronic devices. Here, a site‐selective codoping strategy in which Ca2+ and Y3+ substitute for Bi3+ is applied. The resulting p‐ and n‐type doped BIG films combine state‐of‐the‐art magneto‐optical properties and semiconducting behaviors above room temperature with rather low resistivity: 40 Ω cm at 450 K is achieved in an n‐type Y‐doped BIG; this is ten orders of magnitude lower than that of Y3Fe5O12. High‐resolution electron spectromicroscopy unveils the complete dopant solubility and the charge compensation mechanisms at the local scale in p‐ and n‐type systems. Oxygen vacancies as intrinsic donors play a key role in the conduction mechanisms of these doped BIG films. On the other hand, a self‐compensation of Ca2+ with oxygen vacancies tends to limit the conduction in p‐type Ca/Y‐doped BIG. These results highlight the possibility of integrating n‐type and p‐type doped BIG films in spintronic structures as well as their potential use in gas sensing applications.

Electronic structures of MgO/Fe interfaces with perpendicular magnetization revealed by hard X-ray photoemission with an applied magnetic field

ABSTRACT We have developed hard X-ray photoelectron spectroscopy (HAXPES) under an applied magnetic field of 1 kOe to study the electronic and magnetic states related to the MgO/Fe interface-induced perpendicular magnetic anisotropy (PMA). In this work, we used MgO (2 nm)/Fe (1.5 and 20 nm)/MgO(001) structures to reveal the interface-induced electronic states of the Fe film. Perpendicular magnetization of the 1.5-nm-thick Fe film without extrinsic oxidation of the Fe film was detected by the Fe 2p core-level magnetic circular dichroism (MCD) in HAXPES under a magnetic field, and easy magnetization axis perpendicular to the film plane was confirmed by ex situ magnetic hysteresis measurements. The valence-band HAXPES spectrum of the 1.5-nm-thick Fe film revealed that the Fe 3d electronic states were strongly modified from the thick Fe film and a reference bulk Fe sample due to the lifting of degeneracy in the Fe 3d states near the MgO/Fe interface. We found that the tetragonal distortion of the Fe film by the MgO substrate also contributes to the lifting of degeneracy in the Fe 3d states and PMA, as well as the Fe 3d-O 2p hybridization at the MgO/Fe interface, by comparing the valence-band spectrum with density functional theory calculations for MgO/Fe multilayer structures. Thus, we can conclude that the Fe 3d-O 2p hybridization and tetragonal distortion of the Fe film play important roles in PMA at the MgO/Fe interface. HAXPES with in situ magnetization thus represents a powerful new method for studying spintronic structures.

Antenna-coupled spintronic terahertz emitters driven by a 1550 nm femtosecond laser oscillator

We demonstrate antenna-coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna-coupled devices to those without antennas. Using a 200 μm H-dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42-fold larger THz peak-peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 μm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a commercial fiber-coupled system that is frequently employed in table-top THz time-domain systems.