The gist of it
Ultrasensitive magnetometer using a single atom. – I. Baumgart, J.M. Cai, A. Retzker, M.B. Plenio and Ch. Wunderlich,
Phys. Rev. Lett. 116, 240801 (2016)|ArXiv
The development of highly sensitive methods for the detection of minute fields lies at the heart of quantum metrology and has, over the history of science, led to many discoveries. This motivates the continuous drive towards the development of ever more sensitive metrology methods. Of particular interest in this context are atoms and ions that are trapped in ultra-high vacuum as they can be isolated to a remarkable degree from environmental influences. Still noise will impose limitations and needs to be addressed.
We demonstrate a novel method for sensing magnetic fields and demonstrate that it can achieve the best sensitivity ever realized for a single trapped atomic particle and it can do so over a broad range of frequencies. State-of-the-art magnetometers reach their best sensitivity in a limited frequency-band or do not work at all (for all practical purposes) outside a certain frequency range. The type of magnetometer introduced here could be used to detect fields from direct-current to the gigahertz regime – an unprecedented range of frequencies – using an atom confined to a nanometer-sized region in space. Moreover, the magnetometer is essentially immune against magnetic disturbances and reaches a sensitivity close to the standard quantum limit.
Updated: June 2016
Congratulations, Felipe, for the birth of your new born son, Yunus Caycedo!!!
We hope you have a joyful and healthy journey ahead and we are looking forward to Yunus’ first visit to the institute!
Updated: June 2016
We would like to congratulate Maria for receiving a PhD grant from La Caixa in Spain!
We are sad that you will be leaving us but wish you Good Luck in this next exciting venture!
Updated: June 2016
This April we have celebrated the 1st Table Tennis Tournament of the ITP. It has been an amazing event where many institute members have taken part, either as a participant or as a captivated audience. We had four rounds, each of them full of incredible matches and breathtaking shots that will be remembered forever and ever.
Click here to watch video clip #1
Click here to watch video clip #2
After three weeks of thrilling expectation Ish Dhand has won the finals, obtaining the certificate of the Absolute Winner, donning the victory crown, and gaining the honorable title of PingPong King! Congratulations again!!!
Given the success of the first edition, we are already planning a Table Tennis League while we wait for the second tournament!
Many thanks to Pelayo for organizing it!
Updated: May 2016
We were most happy to welcome Stephanie Wehner (TU Delft) to visit the Institute and deliver the last Faculty Kolloquium of the year 2015. Stephanie presented a very nice and pedagogical talk on the foundations of quantum thermodynamics. She also discussed her recent work on the revision of the concept of Carnot maximal efficiency for quantum thermal machines, which does not only depend on the temperature of the heat reservoirs. These are results in collaboration with Mischa Woods, a former PhD student of the Institute. You can read all details in arXiv:1506.02322
There was also time for discussions Followed by a hearty Schwabian dinner of Goose and Rotkraut at the Zunfthaus in the Fischerviertel to celebrate the Christmas season.
Stephanie was lucky with the weather and also brave enough to climb the tower of the Ulmer Münster (768 steps to reach the top) before catching the train home. The Münster is the one of the five tallest structures to be completed last century, with the steeple of almost 162 meters, the tallest church in the world. Below you can see two fantastic pictures she took in her ascent.
Myung-Joong, Ricardo and Martin have published work showing that a two-level atom coupled to a single-mode cavity field undergoes a second order quantum phase transition when the atomic transition frequency is much larger than the cavity frequency. This result has been chosen as an Editor Suggestion in Physical Review Letters.
You can read the full details in
Quantum Phase Transition and Universal Dynamics in the Rabi Model
Myung-Joong Hwang, Ricardo Puebla, and Martin B. Plenio
Phys. Rev. Lett. 115, 180404 (2015) – Published 29 October 2015
Their work shows that superradiant quantum phase transitions, which are generally studied for systems of thermodynamically many atoms, can actually be investigated within systems containing just a single atom and a single radiation mode. The limit of larger particle number, normally considered as the thermodynamics limit, is replaced by a limit in the coupling strength such that an increasingly large Hilbert space becomes accessible. To confirm that the system behaves like a critical system they studied the Kibble-Zurek mechanism and saw all the right scaling relations.