16:45 〜 17:00
▲ [16p-Z24-13] Magnetic Field Induced Shift of Coulomb Blockade Oscillation in Carbon Nanotube Quantum Dots Filled with Single-Molecule Magnets
キーワード：Single-molecule magnets, Carbon nano-peapods, Coulomb-blockade
Recent advances in understanding the electronic transport properties of individual nanometer-sized material have paved the way for new spintronics devices. Single-molecule magnets (SMMs) have shown promising application in high-density information storage and quantum computing. On the other hand, the hollow nanostructure of single-wall carbon nanotubes (SWCNTs) provides a unique system that coupled nanometer-size objects, such as SMMs, by encapsulation (peapod structure). With the remarkable electronic properties of carbon nanotubes at the nanoscale, this hybrid system is interesting for producing electronic devices that take advantage of the magnetic properties of the encapsulated SMMs.
Here we report the electrical transport characteristics of single-wall carbon nanotubes (SWCNTs) filled with SMMs based on terbium phthalocyanine (TbPc2). Experiments were carried out on SWCNTs transistor devices with a PPMS cryostat using a lock-in technique. The conductance oscillation against the gate voltage (VG) is observed at 2 K. This can be attributed to the Coulomb blockade due to an SWCNT quantum dot, where the VG controls the blockade and tunneling of the electron from the electrodes. When the magnetic field was applied, the Coulomb blockade oscillation is shifted. A similar phenomenon was reported for SWCNT filled with magnetic nanoparticles and attributed to the Magneto-Coulomb effect. We hypothesized that the observed shift was due to a change in the carbon nanotube quantum dot's electrochemical potential triggered by the spin-flip of the single-molecule magnets. This result indicates that peapod structure is potentially useful to probe the magnetization reversal of the encapsulated SMMs to realize a novel molecular spintronics device.
Here we report the electrical transport characteristics of single-wall carbon nanotubes (SWCNTs) filled with SMMs based on terbium phthalocyanine (TbPc2). Experiments were carried out on SWCNTs transistor devices with a PPMS cryostat using a lock-in technique. The conductance oscillation against the gate voltage (VG) is observed at 2 K. This can be attributed to the Coulomb blockade due to an SWCNT quantum dot, where the VG controls the blockade and tunneling of the electron from the electrodes. When the magnetic field was applied, the Coulomb blockade oscillation is shifted. A similar phenomenon was reported for SWCNT filled with magnetic nanoparticles and attributed to the Magneto-Coulomb effect. We hypothesized that the observed shift was due to a change in the carbon nanotube quantum dot's electrochemical potential triggered by the spin-flip of the single-molecule magnets. This result indicates that peapod structure is potentially useful to probe the magnetization reversal of the encapsulated SMMs to realize a novel molecular spintronics device.