Filtering Atoms by Their Spin

Nicolas Faatz, R. Engels, Bernd Breitkreuz +2 more

Since the early days of quantum mechanics hydrogen, as the simplest of all atoms, has been studied or used to investigate new physics. In parallel, this knowledge leads to different applications, e.g. a spin filter to separate metastable hydrogen atoms in single hyperfine substates with electron spin m_s=1/2. Subsequently, this work provides the necessary theory as well as experimental conditions to build a new generation of spin filter which permits the separation of all four individual metastable hydrogen hyperfine states as well as for its isotopes in a corresponding beam.

Rachel Pei Chin Won

Naman Garg, Ankur Kumar, Harish Parthasarathy

The Belavkin filter is a real-time quantum filter for dynamically estimating atomic observables and states based on non-demolition measurements, i.e. measurements that commute at different times and with future values of the observables. This filter is a generalisation of the classical Kushner filter based on quantum mechanics, and we propose to simulate it by using the H-P stochastic equation and the Belavkin equations without randomness. Randomness enters only when we consider the distribution of observables in specific states of the system and bath. We apply the Belavkin filter to estimate the spin of the electron.

Galina A. Nemova

Paola Cappallaro

Nicolas Faatz, R. Engels, Chrysovalantis S. Kannis +2 more

Since the early days of quantum mechanics, hydrogen, as the simplest of all atoms, has been studied or used to investigate new physics. In the past this knowledge has been applied to develop a polarimeter where the initial nuclear polarization of a proton beam could be determined. The key component of this Lamb-shift polarimeter is the so called spin filter, which is able to separate one of four metastable hydrogen hyperfine states by quenching the remaining three hyperfine states to the ground state. Unfortunately, the conventional spin filter is only able to filter two out of the four hyperfine states individually. Therefore, this work provides the necessary theory as well as experimental conditions to build a new generation of spin filter which permits the separation and transmission of any metastable hydrogen hyperfine state as well as for its isotopes in a corresponding beam. This knowledge is applicable for other experiments in different fields of research, e.g. the bound beta decay, axion research or parity violation experiments.