In a one-dimensional (1D) system of interacting electrons, excitations of spin and charge travel at different speeds, according to the theory of a Tomonaga-Luttinger Liquid (TLL) at low energies. However, the clear observation of this spin-charge separation is an ongoing challenge experimentally. We have fabricated an electrostatically-gated 1D system in which we observe spin-charge separation and also the predicted power-law suppression of tunnelling into the 1D system. The spin-charge separation persists even beyond the low-energy regime where the TLL approximation should hold. TLL effects should therefore also be important in similar, but shorter, electrostatically gated wires, where interaction effects are being studied extensively worldwide.The effects of interactions are almost impossible to calculate in a general many-particle system, though they cannot be ignored. However, for a one-dimensional (1D) system, Luttinger, building on an approximation scheme of Tomonaga, constructed a soluble 1D model with infinite linear dispersion and a restricted set of interactions. The solution has 1 arXiv:1002.2782v1 [cond-mat.str-el]

The search for new efficient thermoelectric devices converting waste heat into electrical energy is of major importance. The physics of mesoscopic electronic transport offers the possibility to develop a new generation of nanoengines with high efficiency. Here we describe an all-electrical heat engine harvesting and converting dissipated power into an electrical current. Two capacitively coupled mesoscopic conductors realized in a two-dimensional conductor form the hot source and the cold converter of our device. In the former, controlled Joule heating generated by a voltage-biased quantum point contact results in thermal voltage fluctuations. By capacitive coupling the latter creates electric potential fluctuations in a cold chaotic cavity connected to external leads by two quantum point contacts. For unequal quantum point contact transmissions, a net electrical current is observed proportional to the heat produced.

A scanning tunneling microscope ͑STM͒ with a compact, three-dimensional, inertial slider design is presented. Inertial sliding of the STM tip, in three dimensions, enables coarse motion and scanning using only one piezoelectric tube. Using the same electronics both for scanning and inertial sliding, step lengths of less than 5% of the piezo range were achieved. The compact design, less than 1 cm 3 in volume, ensures a low mechanical noise level and enables us to fit the STM into the sample holder of a transmission electron microscope ͑TEM͒, while maintaining atomic scale resolution in both STM and TEM imaging.

High-aspect ratio Cd1−x Zn x S (x = 0−1) alloy semiconductor nanowires are reported here for the first time using an ethylenediamine (en)-assisted solvothermal approach. The composition of the en−water (en-w) mixed solvent plays a crucial role in determining the morphology and crystalline phase of the alloy nanowires in the middle range of x (i.e., when x approaches 0.5). A phase transformation from hexagonal to cubic was observed for the middle range of x in an en-dominated solvent (en/w, 5:1). Nanowires with hexagonal phases were formed for the entire range of x with increasing water content of the solvent system (en/w, 2:1). The aspect ratio of the nanowires was found to be dependent on the x value as well as solvent composition. Alloy nanowires exhibit photoresponse properties when illuminated under white light. The synthesis technique is modified to synthesize core−shell Cd1−x Zn x S/ZnS nanowires. Enhancement in photoluminescence efficiency is observed with a ZnS shell over the alloy nanowires.