Zero-Shot Composed Image Retrieval with Textual Inversion

Composed Image Retrieval (CIR) aims to retrieve a target image based on a query composed of a reference image and a relative caption that describes the difference between the two images. The high effort and cost required for labeling datasets for CIR hamper the widespread usage of existing methods, as they rely on supervised learning. In this work, we propose a new task, Zero-Shot CIR (ZS-CIR), that aims to address CIR without requiring a labeled training dataset. Our approach, named zero-Shot composEd imAge Retrieval with textuaL invErsion (SEARLE), maps the visual features of the reference image into a pseudo-word token in CLIP token embedding space and integrates it with the relative caption. To support research on ZS-CIR, we introduce an open-domain benchmarking dataset named Composed Image Retrieval on Common Objects in context (CIRCO), which is the first dataset for CIR containing multiple ground truths for each query. The experiments show that SEARLE exhibits better performance than the baselines on the two main datasets for CIR tasks, FashionIQ and CIRR, and on the proposed CIRCO. The dataset, the code and the model are publicly available at https://github.com/miccunifi/SEARLE .Comment: SEARLE repository: https://github.com/miccunifi/SEARLE . CIRCO repository: https://github.com/miccunifi/CIRC

Blocking Temperature Engineering in Exchange-Biased CoFeB/IrMn Bilayer

In this paper, we report on the magnetic and chemical characterization of the exchange-biased CoFeB/IrMn bilayers, grown by magnetron sputtering on a Si-based platform and capped by either a Ru or MgO/Ru overlayer. For Ru capping, the locking temperature monotonously increases with the IrMn thickness within the investigated range (3.5–8 nm). On the contrary, for MgO/Ru capping, the exchange bias is inhibited below 6 nm, whereas above 6 nm, the magnetic behavior is the same of Ru-capped films. The chemical analysis reveals a significant dependence of the Mn content from the capping layer for thin IrMn films (2.5 nm), whereas the difference disappears when IrMn becomes thick (7 nm). Our work suggests that a non-uniform composition of the IrMn films directly affects the exchange coupling at the IrMn/CoFeB interface

Impact of electromagnetic fields and heat on spin transport signals in Y3Fe5O12

Exploring new strategies to perform magnon logic is a key requirement for the further development of magnonbased spintronics. in this paper, we realize a three-terminal magnon transport device to study the possibility of manipulating magnonic spin information transfer in a magnetic insulator via localized magnetic fields and heat generation. the device comprises two parallel pt wires as well as a cu center wire that are deposited on the ferrimagnetic insulator y3fe5o12. while the pt wires act as spin current injector and detector, the cu wire is used to create local magnetostatic fields and additional heat, which impact both the magnetic configuration and the magnons within the y3fe5o12 below. we show that these factors can create a nonlocal signal that shows similar features as compared to an electrically induced magnon flow. furthermore, a modulation of the spin transport signal between the pt wires is observed, which can be partly explained by thermally excited spin currents of different polarization. our results indicate a potential way towards the manipulation of nonlocal magnon signals, which could be useful for magnon logic

Impact of the interplay of piezoelectric strain and current-induced heating on the field-like spin–orbit torque in perpendicularly magnetized Ta/Co20Fe60B20/Ta/MgO film

<p>Spin–orbit torques (SOTs) are known to be the most efficient way to manipulate the magnetization direction by electrical currents. While, conventionally, one symmetry component of the SOTs, namely, the damping-like torque, was considered to play a primary role, recently, the significance of the other component, the field-like torque, has been revised, owing to the non-trivial dynamics it can induce in heavy metal/ferromagnet multilayers. In this work, we first discuss the unusual behavior of the field-like SOT in a Ta/CoFeB/Ta/MgO multilayer system with a reduced magnetic anisotropy and demonstrate an energy-efficient approach to manipulate the magnitude of the SOT effective fields. Finally, our results show a possibility to engineer the anisotropy of the field-like SOTs by piezoelectric strain, which can be potentially attractive for application in spintronics.</p&gt

Orientation-dependent direct and inverse spin Hall effects in Co60Fe20B20

In ferromagnetic metals, the interconversion of spin and charge currents via the spin hall effect and its inverse can depend on the angle between the ferromagnet's magnetization and the spin current polarization direction. here, such a spin-dependent (inverse) spin hall effect is found in the ferromagnetic alloy co60fe20b20. in a nonlocal magnon transport experiment, co60fe20b20 is used either to excite or to detect magnonic spin currents flowing in the ferrimagnetic insulator y3fe5o12. we find that the signal amplitude is significantly modulated by tuning the direction of the co60fe20b20 magnetization. we design a sample structure that prevents direct magnonic coupling between the ferromagnets. thus, we can identify unambiguously an intrinsic electronic origin of the observed effect