Tunable optical chip paves way for new quantum devices

Researchers have created a silicon carbide (SiC) photonic integrated chip that can be thermally tuned by applying an electric signal. The approach could one day be used to create a large range of reconfigurable devices such as phase-shifters and tunable optical couplers needed for networking applications and quantum information processing.

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Ultra-fast optical way to extract critical information from quantum materials

Topological insulators are quantum materials, which, due to their exotic electronic structure, on surfaces and edges conduct electric current like metal, while acting as an insulator in bulk. Scientists have now demonstrated how to tell apart topological materials from their regular — trivial — counterparts within a millionth of a billionth of a second by probing it with ultra-fast laser light.

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2000 atoms in two places at once

The quantum superposition principle has been tested on a scale as never before in a new study. Hot, complex molecules composed of nearly two thousand atoms were brought into a quantum superposition and made to interfere. By confirming this phenomenon — 'the heart of quantum mechanics', in Richard Feynman's words — on a new mass scale, improved constraints on alternative theories to quantum mechanics have been placed.

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New liquid crystals allowing directed transmission of electricity synthesized

Liquid and solid – most people are unaware that there can be states in between. Liquid crystals are representative of one such state. While the molecules in liquids swim around at random, neighboring molecules in liquid crystals are aligned as in regular crystal grids, but the material is still liquid.

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Beyond Einstein: Mystery surrounding photon momentum solved

According to Einstein, light consists of particles (photons) that transfer only quantized energy to the electron of the atom. If the photon's energy is sufficient, it knocks the electrons out of the atom. But what happens to the photon's momentum in this process? Physicists are now able to answer this question. To do so, they developed and constructed and new spectrometer with previously unattainable resolution.

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Curved nanochannels allow independent tuning of charge and spin currents

To increase the efficiency of microchips, 3D structures are now being investigated. However, spintronic components, which rely on electron spin rather than charge, are always flat. To investigate how to connect these to 3D electronics, physicists have created curved spin transport channels. They discovered that this new geometry makes it possible to independently tune charge and spin currents.

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