Recent theories have shown that an electric field can induce a net flow of orbital momentum in common metals and semiconductors, even when crystal field and band structure effects completely quench the orbital magnetism at equilibrium. Specifically, an electric field applied to 3d metals such as Ti, Cr, and Mn can generate a substantial non-equilibrium orbital accumulation, which is comparable...
Artificial spin ice are arrangements of dipolar coupled nanomagnets, which exhibit a range of interesting behaviour. Here, we study an artificial spin ice based on the ruby lattice. This pattern has a complex unit cell with 12 nanomagnets and two lattice constants that define it. By varying the two lattice constants independently, we can change the interaction between nanomagnets. Using x-ray...
The long magnetic reversal time measured for selected nanoparticles cannot be rationalized with crystal, shape and surface anisotropies, suggesting the relevance of structural defects which are observed experimentally. We demonstrate here that the presence of stacking faults or twin boundaries in Co nanoparticles leads to the calculation of a transition rate, the inverse of the reversal time,...
The stray field of micromagnets is currently exploited to manipulate the spin state of electrons confined in semiconductor quantum dots. The manipulation performance depends on the magnetization pattern, which is often assumed to be uniform in the development of micromagnet designs. We question this assumption by comparing micromagnetic simulations and spin qubit experiments and analyze the...
The generation of spin current pulses by laser-driven demagnetization links the field of ultrafast magnetism to spintronics. This work presents the study of spintronic quantities (spin voltage, spin current and spin transport) on the femtosecond time scale by spin and time resolved photoemission experiments. A thin iron sample is excited by an 800 nm laser pulse to measure the chemical...
Magnetoelectric materials exhibit a coupling between their magnetic and electric order parameters, which has lead to a manifestation of different magnetoelectric-driven behavior. Novel magnetoelectric responses now at the forefront of scrutiny for augmenting next-generational technological devices. Here, we present a unique magnetoelectric response. Specifically, we report the ability to...
Complex transition metal oxides exhibit a correlation among their crystal magnetic and electronic orderings. Using advanced growth techniques one can tunee one ordering and influence other correlated ones, creating new macroscopic behaviors not existing in bulk. van der Waals magnetic materials naturally exhibit low dimensional magnetic, optical and transport properties. The novel physical...
The ability to map magnetic field sensitively and on the nanometer-scale – unlike global magnetization or transport measurements – overcomes ensemble or spatial inhomogeneity in systems ranging from arrays of nanometer-scale magnets, to superconducting thin films, to strongly correlated states in van der Waals heterostructures. Local imaging of nanometer-scale magnetization, Meissner currents,...
Remote control of molecular conformation is a challenge in nanotechnology. We realized this on gateable graphene on a SiO2/Si (MOS) structure, where the work function is changed reversibly.
The conformation of CeTi endohedral dimers in C80 evaporated on the graphene was measured with linear dichroism at the Ce_M4,5-edge. The change in orientation of the Ce-Ti ligand field axis is inferred...
X-ray imaging at synchrotrons have enabled a significant advancement in the understanding of the physics driving magnetic systems. Nevertheless, for X-ray imaging at ultrafast timescales, free-electron lasers become a necessity. In my talk, I will present the first results of the X-ray holography magnetic imaging setup recently commissioned at the Maloja endstation at SwissFEL (PSI,...
We present the design and implementation of a new type of scanning Nitrogen-Vacancy magnetic imaging probe with an integrated microwave near-field coupling device for optimized spin manipulation. The microwave coupling loop is directly integrated onto the attachment structure of the scanning probe eliminating the need for external MW delivery solutions. The characterization and the...
The ability to exfoliate van der Waals crystals of magnetic compounds is giving access to a vast, unexplored family of two-dimensional magnetic materials, with a variety of different magnetic ground states. Most of these compounds are semiconductors that offer –besides the possibility to explore magnetism in highly controlled 2D crystals— a new playground to combine magnetic and...
Investigating magnetism in topological materials reveals intriguing correlations between magnetic and electronic states, notably in the magnetic Weyl semimetal Co3Sn2S2. This work employs Lorentz MEM and XMCD-PEEM to explore the temperature- and field-dependent dynamics of magnetic domains in Co3Sn2S2. We observe spontaneous magnetic bubbles of tens of micrometers under zero-field,...
Studies of ultrathin antiferromagnets are highly challenging due to difficulties in probing atomically thin samples with no net magnetization. Here, we present a systematic investigation of magneto-transport in 2D layered van der Waals XY-type antiferromagnet. We observe spin-flop transition and anisotropic magnetoresistance down to bilayer thickness, which are clear indications of long-range...
Tb$_3$N@C$_{80}$ is promising for investigating the magnetism of compressed lanthanides. The ligand field of the N$^{3-}$ anion in C$_{80}$ causes the anisotropic alignment of the magnetic moments of the Tb$^{3+}$, resulting in a frustrated magnetic ground state. A Hamiltonian allowing for tunneling of the Tb$^{3+}$ magnetic moments better explains the paramagnetic behavior of...
In this work, we have studied the effect of intrinsic electric and strain fields, collectively known as the effective field, on the energy level structure of the nitrogen-vacancy (NV) center in diamond. we used pulsed electron spin resonance spectroscopy to resolve the hyperfine structure at zero magnetic field and its vicinity in a polycrystalline diamond. Results revealed characteristic...
