Tailoring the magnetism of GaMnAs films by ion irradiation

Ion-beam modification of the magnetic properties of GaMnAs epilayers

We study the controlled introduction of defects in GaMnAs by irradiating the samples with energetic ion beams, which modify the magnetic properties of the DMS. Our study focuses on the low-carrier-density regime, starting with as-grown GaMnAs films and decreasing even further the number of carriers, through a sequence of irradiation doses. We did a systematic study of magnetization as a function of temperature and of the irradiation ion dose. We also performed in-situ room temperature resistivity measurements as a function of the ion dose. We observe that both magnetic and transport properties…

电子辐照：从测试到材料调控

Electron irradiation: from test to material tailoring

本文展示高能电子辐照可作为材料调控工具，通过控制点缺陷将性能退化转为优势，并在半导体和超导体上验证了该技术的潜力。

Tailoring surface interactions, contact angles, drop topologies and self-assembly using laser irradiation

UV laser irradiation (lambda = 193 nm), below and above damage thresholds, is used to both alter and pattern the surface properties of borosilicate slides to tune and control the contact angle of a water drop over the surface. Large variation exceeding 25 deg using laser processing alone, spanning across both sides of the original contact angle of the surface, is reported. An asymmetric contact angle distribution, giving rise to an analogous ellipsoidal-like drop caplet, is shown to improve convective self-assembly of silica nanoparticles into straighter microwires over a spherical caplet.

Tailoring strain in SrTiO3 compound by low energy He+ irradiation

The ability to generate a change of the lattice parameter in a near-surface layer of a controllable thickness by ion implantation of strontium titanate is reported here using low energy He+ ions. The induced strain follows a distribution within a typical near-surface layer of 200 nm as obtained from structural analysis. Due to clamping effect from the underlying layer, only perpendicular expansion is observed. Maximum distortions up to 5-7% are obtained with no evidence of amorphisation at fluences of 1E16 He+ ions/cm2 and ion energies in the range 10-30 keV.

Tailoring interfacial effect in multilayers with Dzyaloshinskii-Moriya interaction by helium ion irradiation

We show a method to control magnetic interfacial effects in multilayers with Dzyaloshinskii-Moriya interaction (DMI) using helium (He$^{+}$) ion irradiation. We report results from SQUID magnetometry, ferromagnetic resonance as well as Brillouin light scattering results on multilayers with DMI as a function of irradiation fluence to study the effect of irradiation on the magnetic properties of the multilayers. Our results show clear evidence of the He$^{+}$ irradiation effects on the magnetic properties which is consistent with interface modification due to the effects of the He$^{+}$ irradiat…

通过强激光辐照调控外尔半金属中的光电流

Tailoring Photocurrent in Weyl Semimetals via Intense Laser Irradiation

本文提出利用强单色圆偏振激光脉冲在中心对称及非中心对称外尔半金属中产生超快光电流，并通过调控激光螺旋性和椭圆率实现对光电流的调节，拓展了外尔半金属在光电子与量子技术中的应用前景。