Optical tweezers and quantum simulation
In collaboration with Slovenian high-tech company Aresis, we are developing an optical tweezer to manipulate, split, guide and recombine ultracold atoms. One of the main goals is to prepare arrays of atomic ensembles that will be used for quantum simulation with Rydberg atoms.
The idea of quantum memory is to store photons and have the ability to recall them on demand. We are developing a quantum memory based on electromagnetically induced transparency in a cloud of cesium atoms. So far we have achieved a few microseconds long storage time of classical light pulses with atomic vapor and almost a microsecond of storage time with ultracool cesium atoms. We are now working towards longer storage times and higher storage efficiency in both mediums. Furthermore, we are studying the effect of the magnetic field on storage and using multiple read or write pulses.
When non-interacting Bose-Einstein condensate is confined to a quasi one-dimensional channel it will spread due to dispersion as dictated by the Schrödinger equation. The spreading rate can be affected by changing the interaction between the atoms via the Feshbach resonance. If the interaction is set to just the right value, the attraction between atoms exactly compensates the dispersion. In this case the BEC doesn’t spread and we get a bright matter-wave soliton. The maximum number of atoms in a soliton is limited by the frequency of the channel and the interaction between atoms. By setting the inter-atom interaction to different attractive values we are able to create soliton trains with different number of solitons from elongated BECs.
Modulating the interaction between the atoms in a Bose-Einstein condensate (BEC) can give raise to diverse phenomena depending on the frequency and amplitude of shaking. When the frequency of modulation is tuned close to collective mode resonance, Faraday waves appear. At low frequencies granulation of BEC is observed, whereas at high frequencies matter-wave jets are emitted. In our setup atom jets are emitted from a matter-wave soliton in a quasi-one-dimensional optical trap. We are studying the jet number correlations and entanglement.
The quantum technologies based on cold atoms have an enormous potential for innovation both on a fundamental level and in real-world applications such as quantum-based sensors for gravity, acceleration, rotation and magnetic fields. We are developing a high-resolution cold-atom magnetometer with a potential to be used in various fields, including a signal detection in NMR and MRI, as well as NQR, control of magnetic fields in precise experiments, such as in atomic physics or direct measurement of magnetic fields from the heart and brain.