Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0704.2497

Current-Induced Switching of a Single-Molecule Magnet with Arbitrary Oriented Easy Axis

Maciej Misiorny·Józef Barnas
View original source ↗Read source document ↗Export metadata ↓

Abstract

The main objective of this work is to investigate theoretically how tilting of an easy axis of a single-molecule magnet (SMM) from the orientation collinear with magnetic moments of the leads affects the switching process induced by current flowing through the system. To do this we consider a model system that consists of a SMM embedded in the nonmagnetic barrier of a magnetic tunnel junction. The anisotropy axis of the SMM forms an arbitrary angle with magnetic moments of the leads (the latter ones are assumed to be collinear). The reversal of the SMM's spin takes place due to exchange interaction between the molecule and electrons tunneling through the barrier. The current flowing through the system as well as the average z-component of the SMM's spin are calculated in the second-order perturbation description (Fermi golden rule).

Explore related subjects

cond-mat.mes-hallcond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Maciej Misiorny, Józef Barnas. 2007-05-06. Current-Induced Switching of a Single-Molecule Magnet with Arbitrary Oriented Easy Axis. https://arxiv.org/abs/0704.2497

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Tunneling probe-based characterisation of the sp${}^3$ dangling bond on the H-C(100):$2\times1$ surface

The sp${}^3$ dangling bond on the diamond surface plays a critical role in the performance and fabrication of diamond quantum technologies. For the former, the magnetic and electric properties of this defect can impede the performance of quantum sensors and computers. For the latter, the chemical properties of the dangling bond are integral to proposed methods for bottom-up fabrication of scalable diamond quantum devices. In pursuit of high-performance, scalable diamond quantum technology, tunnelling probe-based techniques offer the ability to create and modify the sp${}^3$ dangling bond with atomic-scale precision. However, these capabilities cannot be realised either deterministically or at scale without a means of identifying the sp${}^3$ dangling bond amidst the myriad of other defects on the diamond surface. Consequently, in this work we provide a comprehensive experimental and theoretical framework for STS-based characterisation of the sp${}^3$ defect on the H-terminated (100) diamond surface. This capability provides the foundation for future tunnelling probe studies in the modification of dangling bonds.

cond-mat.mes-hall↗
arXiv2026

Damping-dependent thermalization of neighboring nanomechanical resonators below 1 mK

The position noise spectra of six drums on a single chip were measured on a single cooldown below 1.3 kelvin. Cryostat temperatures as low as 0.7 mK were achieved. The temperature dependence of the resonance frequency and linewidth of the drum modes was analyzed in the framework of the tunneling two level system (TLS) model. Departures of the resonance frequency and the position noise power from the expected logarithmic and linear temperature dependences, respectively, were interpreted as indications of thermal decoupling from the cryostat. This previously unexplored measurement configuration revealed that similar neighboring drums on a single chip may be at different temperatures. At the lowest temperatures, some drums exhibited excess damping that decreased with temperature. The magnitude of the excess damping of the drums was correlated with the thermal coupling of their TLS to the cryostat. In the case of one drum, a temporary increase in its damping coincided with a decrease in its mode temperature. The thermalization of the TLS to the cold finger was independent of pump power, pulse tube state and temperature of the pre-cooling stages of the cryostat. These results suggest that thermalization of nanomechanics to the cryostat can be mediated by TLS damping rather than clamping loss and may impact efforts to extend the coherence of mechanical resonators.

cond-mat.mes-hall↗
arXiv2026

Symmetry-enabled tunable square-lattice Hubbard models in $Γ$-valley moiré bilayers

Square-lattice moiré systems provide a promising route for quantum simulation of Hubbard physics, yet electrically tunable realizations of the hopping ratio $t'/t$ have so far been limited to specific valley configurations. A natural question is whether the same tunability can be extended to the more broadly occurring $Γ$-valley systems. Here we identify a symmetry-controlled route for realizing electrically tunable square-lattice Hubbard models in $Γ$-valley twisted homobilayers. At small twist angles, an emergent layer-exchange symmetry separates the low-energy states into flat bands localized on two nested square sublattices, suppressing inter-sublattice hopping. An interlayer displacement field breaks this symmetry and induces controllable hybridization between the sublattices, enabling continuous tuning of the $t'/t$ ratio over a wide range while preserving an effective single-band description. We further establish a formal correspondence between $Γ$- and M-valley moiré systems, revealing them as different symmetry limits of a unified framework for tunable square-lattice Hubbard models. Our results uncover a general symmetry principle underlying displacement-field tunability and extend electrically controllable square-lattice Hubbard physics to a broad family of $Γ$-valley materials.

cond-mat.mes-hall↗