arXiv subjects

Félix Casanova

Publications and source records attributed to Félix Casanova.

4 recordsLinked to original sources

arXiv2025

Colloquium: A critique on van der Waals and two-dimensional magnets

Magnetic two-dimensional (2D) crystals were isolated about a decade ago, triggering a tremendous research activity worldwide. This colloquium raises a stiff question: what is really new about them? At first sight, they seem to be purer implementations of 2D spin models than traditional systems such as ultra-thin films. Yet, they partly realized their promises so far, and whether they give fresh perspectives on long-standing predictions in statistical physics is still an open question. Undoubtedly, they are uniquely amenable to electric-field effect, susceptible to mechanical deformation, and sensitive to moirés, for example. They represent interesting platforms for exploring, challenging, or simply revisiting a wide range of phenomena in condensed matter magnetism. This colloquium intends to offer a critical, yet not necessarily skeptical, overview of the field, clarifying what we believe could be unique with 2D magnets, related quasi-2D van der Waals magnets, and their heterostructures.

cond-mat.mtrl-sci↗

arXiv2024

Unveiling intrinsic bulk photovoltaic effect in atomically thin ReS2

The bulk photovoltaic effect (BPVE) offers a promising avenue to surpass the efficiency limitations of current solar cell technology. However, disentangling intrinsic and extrinsic contributions to photocurrent remains a significant challenge. Here, we fabricate high-quality, lateral devices based on atomically thin ReS2 with minimal contact resistance, providing an optimal platform for distinguishing intrinsic bulk photovoltaic signals from other extrinsic photocurrent contributions originating from interfacial effects. Our devices exhibit large bulk photovoltaic performance with intrinsic responsivities of 1 mA/W in the visible range, without the need for external tuning knobs such as strain engineering. Our experimental findings are supported by theoretical calculations. Furthermore, our approach can be extrapolated to investigate the intrinsic BPVE in other non-centrosymmetric van der Waals materials, paving the way for a new generation of efficient light-harvesting devices.

cond-mat.mes-hall↗

arXiv2023

All-electrical detection of the spin-charge conversion in nanodevices based on SrTiO3 two-dimensional electron gases

The Magnetoelectric Spin-Orbit (MESO) technology aims to bring logic into memory by combining a ferromagnet with a magnetoelectric (ME) element for information writing, and a spin-orbit (SO) element for information read-out through spin-charge conversion. Among candidate SO materials to achieve a large MESO output signal, oxide Rashba two-dimensional electron gases (2DEGs) have shown very large spin-charge conversion efficiencies, albeit mostly in spin-pumping experiments. Here, we report all-electrical spin-injection and spin-charge conversion experiments in nanoscale devices harnessing the inverse Edelstein effect of SrTiO3 2DEGs. We have designed, patterned and fabricated nanodevices in which a spin current injected from a cobalt layer into the 2DEG is converted into a charge current. We optimized the spin-charge conversion signal by applying back-gate voltages, and studied its temperature evolution. We further disentangled the inverse Edelstein contribution from spurious effects such as the planar Hall effect, the anomalous Hall effect or the anisotropic magnetoresistance. The combination of non-volatility and high energy efficiency of these devices could potentially lead to new technology paradigms for beyond-CMOS computing architectures.

cond-mat.mes-hall↗

arXiv2023

Spin Hall Induced Magnetization Dynamics in Multiferroic Tunnel Junction

The combination of spin-orbit coupling driven effects and multiferroic tunneling properties was explored experimentally in thin Pt/Co/BTO/LSMO multilayers. The presence of a Pt heavy metal allows for the spin current-induced magnetization precession of Co upon radio-frequency charge current injection. The utilization of a BTO ferroelectric tunnel barrier separating the Co and LSMO ferromagnetic electrodes gives rise to both tunneling-magnetoresistance and electroresistance. Using the spin-orbit torque ferromagnetic resonance, the maganetization dynamics of the Co/Pt bilayers was studied at room temperature. Unexpectedly the magnetization dynamics study in the same geometry performed at low temperature reveals the existence of both Co and LSMO resonance peaks indicating efficient spin current generation both using the spin Hall effect in Pt and spin pumping in LSMO that tunnel via the BTO barrier.

cond-mat.mes-hall↗