For the last three decades, quantum physics has promised a revolution in information processing - faster computers, better sensors and more secure communication. Today, those promises are becoming reality.
In this work, we experimentally explored various aspects of quantum information processing by encoding the (spin) information into individual ions confined in a Paul trap. Engineered laser...
Many-body entanglement is an active field of research due to both its fundamental aspects and its potential applications in quantum information processing and metrology. We study correlations between spins in spatially separated regions (A and B) in a 87Rb Bose-Einstein condensate which violate an EPR steering inequality.
Such correlations allow one to predict the results of...
We use tunable cavities with nanoscale defects to create zero-dimensional exciton-polaritons. Data on the strong coupling as well as mode properties are shown as a function of cavity detuning. At ambient conditions, we observe polariton condensation with strong lateral confinement on the wavelength scale.
As a building block towards extended lattices, we realize two coupled cavities by...
We demonstrate the experimental creation and detection of a single phonon Fock state at room-temperature using two-color pump-probe excitation and spectrally-resolved time-correlated photon counting [1]. Our scheme is inspired by recent proposals and experiments in cavity quantum optomechanics, but we anticipate that it will be applicable on a broad range of organic and inorganic materials,...
Motional Sideband Asymmetry is a signature of the quantum regime of mechanical oscillators. It has been studied in several optomechanical systems as self-calibrated thermometry. We present sideband asymmetry measurement of a nano-optomechanical system sideband-cooled close to the ground state probing simultaneously with red- and blue-detuned tones. We show that this can exhibit an artificially...
When measuring the position of a mechanical oscillator, quantum mechanics imposes a strict limit on the attainable precision: Any reduction of imprecision leads to increased quantum backaction of the measuring probe on the oscillator. This quantum limit can be circumvented, in principle allowing to indefinitely reduce imprecision, by monitoring only a single quadrature of the oscillator. Such...
CSEM is developing quantum metrology and sensing devices based on in-house MEMS atomic vapor cells with integrated functionalities [1]. Such cells were successfully integrated in <5mm flat miniature atomic clock physics packages with state-of-the-art performance [2]. In the context of NMR gyroscopes, parameters like relaxation times of noble atoms nuclear spins as a function of cell size and...
Compact Rb vapor-cell atomic clocks are high-stability frequency references for applications ranging from telecommunication to satellite navigation systems. For achieving state-of-the-art clock operation, stringent requirements apply to the microwave resonator cavity used in the clock. Here we report on a compact microwave cavity produced by additive manufacturing of a polymer followed by...
Sensitive spectroscopic methods for trace gas detection in the mid-infrared range often involve a modulated quantum cascade laser (QCL). Pure frequency modulation (FM) or amplitude modulation (AM) is preferable, while modulating the QCL current results in a combined AM-FM. Here, we demonstrate pure AM or FM realized with a QCL equipped with an integrated resistive heater (IH). By applying...
Recently, researchers at XFELs have demonstrated the ability to produce two intense femtosecond x-ray pulses with controlled time delay and color. Here we utilize these capabilities to perform X-ray pump/ X-ray probe photoelectron spectroscopy with high temporal resolution. This allows us to observe electronic and nuclear dynamics in core excited states and to follow how an initially local...
