About QUINST

Quantum mechanics is at the heart of our technology and economy - the laser and the transistor are quantum devices - but its full potential is far from being realized. Recent technological advances in optics, nanoscience and engineering allow experimentalists to create artificial structures or put microscopic and mesoscopic systems under new manipulable conditions in which quantum phenomena play a fundamental role.

Quantum technologies exploit these effects with practical purposes. The objective of Quantum Science is to discover, study, and control quantum efects at a fundamental level. These are two sides of a virtuous circle: new technologies lead to the discovery and study of new phenomena that will lead to new technologies.

Our group's aim is  to control and understand quantum phenomena in a multidisciplinary intersection of  Quantum Information, Quantum optics and cold atoms, Quantum Control, Spintronics, Quantum metrology, Atom interferometry, Superconducting qubits and Circuit QED and Foundations of Quantum Mechanics.

 

 

Latest events

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Ramón Muñoz Tapia (Seminar)

When end where

10/03/2016

Description

Location: Seminar room of the Department of Theoretical Physics & the History of Science
Time      Thursday, 15 October, at 15:00 pm


Title:    Scavenging quantum information

Abstract: Given an unknown state that has already been measured optimally, can one still extract  any information about the original unknown state? Clearly, after a maximally informative measurement, the state of the system ‘collapses' into a post-measurement state from which the same observer cannot obtain further information about the original state of the system. However, the system still encodes a significant amount of information about the original preparation for a second observer who is unaware of the actions of the first one.  I present how a series of independent observers can obtain, or scavenge, information about the unknown state of a system when they sequentially measure it. I also present some interesting variants on how distribute information among observers.

In particular, I consider the scenario where a finite number of observers estimate the state with equal fidelity, regardless of their position in the measurement sequence; and the scenario where all observers use an identical measurement apparatus chosen so that a particular observer's estimation fidelity is maximized.

I finally present some recent developments where the reuse of the systems is applied in the context of discrimination of states.