Cotunneling signatures of Spin-Electric coupling in frustrated triangular molecular magnets

Abstract

The ground state of frustrated (antiferromagnetic) triangular molecular magnets is characterized by two total-spin $S=1/2$ doublets with opposite chirality. According to a group theory analysis [M. Trif \textit{et al.}, Phys. Rev. Lett. \textbf{101}, 217201 (2008)] an external electric field can efficiently couple these two chiral spin states, even when the spin-orbit interaction (SOI) is absent. The strength of this coupling, $d$, is determined by an off-diagonal matrix element of the dipole operator, which can be calculated by \textit{ab-initio} methods [M. F. Islam \textit{et al.}, Phys. Rev. B \textbf{82}, 155446 (2010)]. In this work we propose that Coulomb-blockade transport experiments in the cotunneling regime can provide a direct way to determine the spin-electric coupling strength. Indeed, an electric field generates a $d$-dependent splitting of the ground state manifold, which can be detected in the inelastic cotunneling conductance. Our theoretical analysis is supported by master-equation calculations of quantum transport in the cotunneling regime. We employ a Hubbard-model approach to elucidate the relationship between the Hubbard parameters $t$ and $U$, and the spin-electric coupling constant $d$. This allows us to predict the regime in which the coupling constant $d$ can be extracted from experiment.

References in corpus (20)

• Coherent control of a single electron spin with electric fields
• Molecular Transport Junctions: Vibrational Effects
• Will spin-relaxation times in molecular magnets permit quantum information processing?
• Spin qubits with electrically gated polyoxometalate molecules
• Quantum phase transition in a single-molecule quantum dot
• Spin-Electric Coupling in Molecular Magnets
• Kinetic Equations for Transport Through Single-Molecule Transistors
• Tuning the Kondo effect with a mechanically controllable break junction
• Electronic Orbital Currents and Polarization in Mott Insulators
• Electric Field Controlled Magnetic Anisotropy in a Single Molecule
• Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes
• Electronic excitations of a single molecule contacted in a three-terminal configuration
• Electronic excitation spectrum of metallic carbon nanotubes
• Electric dipoles on magnetic monopoles in spin ice
• Theory for transport through a single magnetic molecule: Endohedral N@C60
• Cotunneling and non-equilibrium magnetization in magnetic molecular monolayers
• First-principle studies of the spin-orbit and the Dzyaloshinskii-Moriya interactions in the \{Cu${}_3$\} single-molecule magnet
• Imaging a 1-electron InAs quantum dot in an InAs/InP nanowire
• Tunneling through magnetic molecules with arbitrary angle between easy axis and magnetic field
• Entanglement in a three spin system controlled by electric and magnetic field