In a magnetic tunnelling junction (MTJ) with perpendicular magnetic anisotropy (PMA), offset field (Ho) of the free layer is usually controlled by using a synthetic antiferromagnetic (SAF) coupling structure, which is composed of an antiferromagnetic coupling (AFC) layer sandwiched by two ferromagnetic (FM) layers. However, Ho increases significantly as the size of MTJ devices shrinks to accommodate high density. In addition, magnetostatic field in PMA SAF structure tends to destabilize the antiferromagnetic (AFM) alignment of the SAF layers, in contrast to the in-plane anisotropy SAF, where the closed flux forms stable AFM magnetic configuration. Here, we present a double SAF structure to control Ho, while maintaining high magnetic stability of the reference layer (RL). The double SAF consists of FM1/AFC/FM2/AFC/FM3 multilayer. An AFM layer like PtMn is added to further stabilize the magnetic configuration of the double SAF. As the magnetization of other FM layers (FM1 and FM2) is aligned oppositely, the magnetostatic field acting on the RL (FM3) layer is significantly reduced due to cancellation effect from its adjacent layers. Both simulation and experimental results demonstrate that the double SAF layers provide high stability for the RL in addition to the reduction of Ho. Our results on MTJ devices show that the AFM pinned double SAF has the highest RL stability. The RL switch rate decreases as the thickness of the CoFe inserted layer between AFM and the pinned layer (Co/Pt multilayer) increases due to improved exchange coupling.

The development of high‐efficiency compact non‐mechanical beam tuning devices has attracted a lot of attention for light detection and ranging, augmented reality display, and chip‐to‐chip communication. Owing to the fast wavefront manipulation in an ultra‐thin dimension, metasurfaces have been regarded as potential substitutes for traditional tunable optical components toward further miniaturization and low power consumption. However, most beam tuning metasurfaces currently are polarization‐sensitive and designed to work in reflection mode, which limit their applications in integrated optical systems for full‐range steering. In this paper, a transmission mode polarization‐insensitive beam switching metasurface based on nonvolatile phase‐change material Ge2Sb2Te5 is proposed and experimentally demonstrated at the telecommunication wavelength. The high transmission efficiency with a large switching angle of up to 75° is achievable for potentially full‐range beam steering applications. As a proof of concept, the transmitted beam with a switching angle of 15° and directivity of 82.4% is demonstrated. In addition, by controlling the phase transition in the intermediate states, the metasurface can be used as a tunable beam splitter to control the ratio of the beam power between two predesigned transmission angles. The demonstrated phase‐change metasurfaces pave the way for achieving high‐efficiency dynamic beam steering for various important applications.

BackgroundUnresectable hepatocellular carcinoma (u-HCC) still accounts for the majority of newly diagnosed HCC which with poor prognosis. In the era of systemic therapy, combination therapy with programmed cell death protein-1 (PD-1) inhibitors and tyrosine kinase inhibitors (TKIs) has become mainstream. Hepatic arterial infusion chemotherapy (HAIC) as a local treatment has also shown a strong anti-tumor effect. This study aimed to investigate the efficacy and safety of HAIC, PD-1 inhibitors plus TKIs for u-HCC.MethodsThis retrospective study included patients with initially u-HCC between October 2020 to April 2022 who had received at least one cycle of therapy with HAIC, PD-1 inhibitors plus TKIs. The primary outcome included overall response rate (ORR), the disease control rate (DCR), surgical conversion rate, progression-free survival (PFS) and treatment-related adverse events.ResultsA total of 145 patients were included in the study. The median treatment cycle of HAIC and PD-1 inhibitors were 3 and 4, respectively. According to the modified RECIST criteria, the best ORR was 57.2% (83/145), 9 had achieved complete response (CR), DCR was 89.7% (130/145). Median time to achieve CR or PR was 65 days. Surgical conversion rate was 18.6% (27/145), seven patients (7/27,25.9%) achieved pathological complete response (pCR). The median follow-up was 12.5 months (4.5-20 months), and the median PFS was 9.7 months. Subgroup analysis showed that Child-pugh A patients had higher DCR (92.2% vs 79.3%, p=0.041) than Child-pugh B patients, as well as increased successful conversion rate (22.4% vs 3.4%, p=0.019). Patients without vascular invasion and extrahepatic metastases showed higher PR (63.4% vs 43.3%, p<0.05) and ORR (73.2% vs 50.0%, p<0.05) than those with vascular invasion. The ORR (73.2% vs 45.5%, p<0.05) and DCR (95.1% vs 78.8%, p<0.05) were also significantly better than those of patients with extrahepatic metastases. HAIC regimen was not related to efficacy (All p>0.05). The incidence rate of grade 3/4 treatment-related AEs was 17.7% without fatal events.ConclusionThe triple combination therapy of HAIC and PD-1 inhibitors plus TKIs for patients with initially unresectable HCC exhibited satisfactory efficacy with tolerable toxicity.