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Silicon p(+)-i-n(+) diode Mach-Zehnder electrooptic modulators having an ultra-compact length of 100 to 200 mum are presented. These devices exhibit high modulation efficiency, with a V(pi)L figure of merit of 0.36 V-mm. Optical modulation at data rates up to 10 Gb/s is demonstrated with low RF power consumption of only 5 pJ/bit.

We report a new method to fabricate electrode-embedded multiple nanopore structures with sub-10 nm diameter, which is designed for electrofluidic applications such as ionic field effect transistors. Our method involves patterning pore structures on membranes using e-beam lithography and shrinking the pore diameter by a self-limiting atomic layer deposition process. We demonstrate that 70-80 nm diameter pores can be shrunk down to sub-10 nm diameter and that the ionic transport of KCl electrolyte can be efficiently manipulated by the embedded electrode within the membrane.

Dynamic state switching in nonlinear multiferroic cantilevers Appl. Phys. Lett. 101, 043506 (2012) Nanomagnetism of cobalt ferrite-based spin filters probed by spin-polarized tunneling Appl. Phys. Lett. 101, 042409 (2012) Magnetic Schottky diode exploiting spin polarized transport in Co/p-Si heterostructure Appl. Phys. Lett. 100, 262402 (2012) Concepts and steps for the realization of a new domain wall based giant magnetoresistance nanowire device: From the available 24 multiturn counter to a 212 turn counter Exchange biased magnetic tunnel junction ͑MTJ͒ structures are shown to have useful properties for forming magnetic memory storage elements in a novel cross-point architecture. MTJ elements have been developed which exhibit very large magnetoresistive ͑MR͒ values exceeding 40% at room temperature, with specific resistance values ranging down to as little as ϳ60 ⍀͑m͒ 2 , and with MR values enhanced by moderate thermal treatments. Large MR values are observed in magnetic elements with areas as small as 0.17 ͑m͒ 2 . The magnetic field dependent current-voltage characteristics of an MTJ element integrated with a silicon diode are analyzed to extract the MR properties of the MTJ element itself.

Phase-change storage is widely used in optical information technologies (DVD, CD-ROM and so on), and recently it has also been considered for non-volatile memory applications. This work reports advances in thermal data recording of phase-change materials. Specifically, we show erasable thermal phase-change recording at a storage density of 3.3 Tb inch(-2), which is three orders of magnitude denser than that currently achievable with commercial optical storage technologies. We demonstrate the concept of a thin-film nanoheater to realize ultra-small heat spots with dimensions of less than 50 nm. Finally, we show in a proof-of-concept demonstration that an individual thin-film heater can write, erase and read the phase of these storage materials at competitive speeds. This work provides important stepping stones for a very-high-density storage or memory technology based on phase-change materials.

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We characterize inductors fabricated from ultra-thin, approximately 100 nm wide strips of niobium (Nb) and niobium nitride (NbN). These nanowires have a large kinetic inductance in the superconducting state. The kinetic inductance scales linearly with the nanowire length, with a typical value of 1 nH µm(-1) for NbN and 44 pH µm(-1) for Nb at a temperature of 2.5 K. We measure the temperature and current dependence of the kinetic inductance and compare our results to theoretical predictions. We also simulate the self-resonant frequencies of these nanowires in a compact meander geometry. These nanowire inductive elements have applications in a variety of microwave frequency superconducting circuits.

We observe a novel signature of coherent transport in the nonequilibrium current fluctuations of a diffusive metallic conductor shorter than the electron phase-breaking length. Under illumination with monochromatic microwaves, the shot noise develops features at voltages corresponding to the photon energies, V nhn͞e, which are oscillatory functions of the microwave power, while the conductance and the I-V curve are unaffected. The observed effect bears a strong resemblance to photon-assisted tunneling, although this marks the first demonstration in a linear system, and in a system without an explicit tunnel barrier. [S0031-9007(98)05538-0] PACS numbers: 73.50. Td, 73.23.Ps, 73.50.Mx, 73.50.Pz Studies of the nonequilibrium current fluctuations have recently emerged as a probe of various mesoscopic systems [1]. The nature of the shot noise can reveal information about the transport which is not evident merely by examining the conductance or the time-averaged transport. For example, correlations due to the Fermi statistics of the electrons can lead to a partial suppression of the shot noise [2,3]. It has been demonstrated [4,5] that even a metallic wire will produce shot noise, provided that its length is short compared to the electron-electron inelastic length, L ee . Time-dependent phenomena in nanostructured systems have also become an active area of research lately [6], and it is interesting to ask what the effect of a time-dependent potential on the current fluctuations might be. Indeed, Lesovik and Levitov [7] recently proposed a new two-particle interference phenomenon, the "nonstationary Aharonov-Bohm effect," which should be observable in the shot noise of a phase-coherent conductor under a high-frequency excitation. As we describe below, this phenomenon is formally identical to the process of "photon-assisted tunneling" (PAT) [8], but applied to shot noise of the system rather than its current-voltage characteristic.In this Letter, we present measurements of the nonequilibrium noise of a diffusive, phase-coherent metallic conductor in the presence of both a high-frequency (2-40 GHz) ac excitation and a dc bias. The noise displays features generated by the time-dependent excitation that bear all the hallmarks of photon-assisted tunneling. Because of the linear nature of the conductance in this mesoscopic system, however, the photon-assisted signatures appear only in the noise, not in the conductance.The theory of photon-assisted tunneling [8] was developed some time ago to explain the features observed [9] in superconducting tunnel junctions when they were illuminated with microwave radiation. It was extended to derive the quantum-limited performance [10] of heterodyne detectors based on these devices. More recently, PAT has been demonstrated in a variety of systems, including semiconductor quantum dots [11], metallic singleelectron transistors [12], semiconductor superlattices [13], and other dual-barrier semiconductor devices [14]. In all of these systems, the conductance displays a strong nonlinearity...