The Institute for Theoretical Physics offers the following seminars:
Muonic hydrogen, a proton orbited by a negative muon, is one of the most basic atomic systems. A few years ago, we have measured the Lamb shift in muonic hydrogen (energy difference between 2S and 2P states) with infrared laser spectroscopy in a pioneering experiment at the Paul Scherrer Institute (PSI). Combined with QED calculations we determined the proton radius (root-mean-square charge radius). Our value is 4% smaller and deviates significantly from the previous values from electron-proton scattering and hydrogen spectroscopy. This discrepancy in a basic field of particle physics created a lot of theoretical investigations and initiated new experiments, but the "proton radius puzzle" is still unsolved today. I will give an overview about the present status, including new data from muonic deuterium and helium.
ETH Science City HPV G 4 - Wed 27.05.2015 16:15
Colloidal nanocrystals are crystals of semiconductor 2-12 nanometers in diameter that are grown in rapid, solution-based chemical reactions. They have recently found commercialization in TV displays and are of promise for solar cells due to their ability to be manufactured at low-cost and their attractive optical properties, such as size-dependent bandgaps. This talk presents recent work using electronic, optical, and neutron spectroscopies along with ab initio and empirical simulations that has yielded insights into the mechanisms at play in these quantum systems and ways they can be engineered to obtain higher performance materials and devices.
ETH Science City HPV G 4 - Wed 20.05.2015 16:15
Quasicrystals are exotic materials that have symmetries once thought to be impossible for matter. The first known examples were synthesized in the laboratory 30 years ago, but could Nature have beaten us to the punch? This talk will describe the search to answer this question, resulting in one of the strangest scientific stories you are ever likely to hear.
ETH Science City HPV G 4 - Wed 6.05.2015 16:15
Measuring neutron star radii and constraining the mass distributions of neutron stars and Galactic black holes offer the unique possibility of probing the equation of state of cold, ultradense matter. I will talk about the tremendous recent developments in these areas and discuss how applying statistical techniques on new data reveals the evolution of these compact objects. I will also show how the tightly constrained radii and the discovery of two solar mass pulsars have led to the first astrophysical inference of the equation of state of ultradense matter.
ETH Science City HPV G 4 - Wed 29.04.2015 16:15
In this talk, the basic functional principle of a quantum computer will be reviewed. It will be shown how strings of trapped ions can be used to build a quantum information processor and how basic computations can be performed using quantum techniques. In particular, the quantum way of doing computations will be illustrated by analog and digital quantum simulations and the basic scheme for quantum error correction will be introduced and discussed. Scaling-up the ion-trap quantum computer can be achieved with interfaces for ion-photon entanglement based on high-finesse optical cavities and cavity-QED protocols, which will be exemplified by recent experimental results.
ETH Science City HPV G 4 - Wed 22.04.2015 16:15