A single atom noise probe operating beyond the Heisenberg limit

  According to the Heisenberg uncertainty principle, the energy or frequency uncertainty of a measurement can be at the best inversely proportional to the observation time (TT). The observation time in an experiment using a quantum mechanical probe is ultimately limited by the coherence time of the probe....

Single atom energy-conversion device with a quantum load


  We report on a single atom energy-conversion quantum device operating as an engine, or a refrigerator, coupled to a quantum load. The “working fluid” consists of the two optical levels of an ion, while the load is one of its vibrational modes, cooled down to the quantum regime. We explore two important differences with classical engines: (i) the presence of a strong generic coupling interaction between engine and load which can induce correlations between them; (ii) the use of non-thermal baths. We examine the ergotropy of the load, which indicates the maximum amount of energy of the load extractable using solely unitary processes. We show that ergotropy rises with the number of engine cycles despite an increase in the entropy of the load. The increase of ergotropy of the load points to the possibility of using the phonon distribution of a single atom as a form of quantum battery.

High resolution spectroscopy on Te2: New lines for reference


  Ro-vibrational spectra of different electronic states of molecules are often used as absolute wavelength or frequency standards. These standards are also used to mitigate any slow drift of laser frequency during an experiment. In the precision experiment, the two most commonly used molecular standards are iodine and tellurium, both are homo-nuclear diatomic molecules. The former is mostly used as standard for the long wavelength (600–900 nm) region, while the tellurium spectrum is widely used in short wavelength (400–550 nm) including near ultraviolet. A comprehensive data on tellurium spectra can be obtained from the tellurium atlas [1]. However near the 455 nm range where a number of important atomic resonance line, the atlas provides no significant data. We have performed high resolution modulation transfer spectroscopy (MTS) on tellurium molecule in a hot cell in the region close to 455 nm wavelength thereby obtained more than 100 new spectral lines which were not observed before. The linewidth of each of these peaks is about a few tens of MHz, making them suitable for laser frequency locking.


Tellurium has new reference lines
Phonon dynamics in ion traps
An exacting transition probability ...
Optical Barium Ion Qubit
Magnetic coherent population trapping in a single ion

Squeezing Enhances Quantum Synchronization



Angelina and Sanjit joins the group

More about past events can be found here

© 2016 by Mukherjee

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