Research

Research at Roman Schnabel's group at the Institute for Quantum Physics covers a wide range of topics. Here you will find details about the individual projects.

Squeezed light

The word "squeezed" is a technical term in quantum physics and describes states whose quantum mechanical uncertainty (over a certain parameter range) is smaller than that of the corresponding ground state. This is remarkable because the ground state has no quantum excitation, while a squeezed state does. Squeezed states (like Fock states) have a nonclassical Glauber-Sudarshan P function and thus belong to the class of nonclassical states. Read on

Gravitational-wave detection

Gravitational waves are emitted by accelerated masses and manifest themselves as oscillations of space-time that propagate at the speed of light. Gravitational waves can be measured through changes in distance between "freely falling" test masses. (Meaning gravitational forces accelerate masses according to Newtons law F = m·a.) Gravitational-wave detectors are Michelson laser interferometers whose mirrors... Read on

ERC-project MassQ - quantum physics of massive objects

There are currently two fundamental theories successfully describing our world: Quantum theory e.g. accurately predicts the absorption and emission of light by atoms, while the general theory of relativity is concerned with gravitation, the force emanating from masses which governs the dynamics of planets, galaxies and black holes. Read on

Quantum communication and entanglement

Quantum communication uses properties of quantum uncertainty to build secure communication networks. An important role is played by entangled states of light. If two rays of light are entangled, this is manifested by correlations in their uncertainties. If "A" and "B" share an entangled system, then measurements... Read on