Terahertz sensing using ferroelectric nanowires

Abstract

Molecular dynamics simulations are used to study the interaction of ferroelectric nanowires with terahertz (THz) Gaussian-shaped pulses of electric field. The computational data indicate the existence of two interaction scenarios that are associated with 'lossless' and dissipative, or 'lossy', interaction mechanisms. A thermodynamical approach is used to analyze the computational data for a wide range of THz pulses. The analysis establishes the foundation for understanding the nanowires' response to the THz pulses and reveals the potential of ferroelectric nanowires to function as nanoscale sensors of THz radiation. Various aspects of this THz nanosensing are analyzed and discussed.

Controllable deformation of salt water-filled carbon nanotubes using an electric field with application to molecular sieving

“…The electric field intensity was on the order of 0.05 ∼ 3.0 V Å −1 . The electric field intensity adopted here was comparable to that of the previous MD simulations on the water molecules [39,40] and still within the range of the electric field used in laboratories [25][26][27][28][29]. An initial equilibrium was performed on the simulation system for 0.5 ns with a time step of 1 fs, and then the salt water-filled CNTs under each electric field of different intensities were equilibrated for 0.4 ns.…”

“…For ionic solution-filled CNTs, it is speculated that the CNTs might present various evident deformation modes driven by internal ions under an external electric field. For instance, under an electric field of intensity 2.0 V Å −1 (comparable to the average local electric field within the condensed phase of water [24] and in the range of the electric field used in laboratories [25][26][27][28][29]), the electric field force of ten ions with elementary charge is about 32 nN. Such a force can elongate (12,12) CNTs with a length of 100 Å by about 1.89 Å (see supplementary information 1), and a slighter force can even induce more obvious bending deflection because of the weak bending rigidity of CNTs [30,31].…”

All-Mechanical Polarization Control and Anomalous (Electro)Mechanical Responses in Ferroelectric Nanowires

“…Piezoelectric and ferroelectric nanowires are promising candidates for nanoscale functional applications, − including biomedical electronics, self-powered wearable and human activity monitoring devices, and multienergy harvesting . For example, piezoelectric zinc-oxide nanowires were found to function as nanogenerators for self-powered nanodevices − where they can produce the output current of 0.6 μA and associated current density of 20 μA/cm 2 , while sodium–potassium niobate nanorods were reported to have the short-circuit current of 5.0 μA .…”

Ferroelectric instability in nanotubes and spherical nanoshells

“…Ferroelectric nanoparticles receive a considerable research attention [1][2][3][4][5][6][7][8][9][10][11][12][13] and novel fabrication methods are being developed [14,15]. The case of ferroelectric nanotubes and nanoshells is particularly interesting, as their specific topology can be exploited for engineering additional functionalities relevant for technological applications [1,2,16].…”