A team of
researchers from Austria is pushing the envelope of quantum computing through
high-precision control of the quantum entanglement phenomenon. Experimental
physicist Rainer Blatt, at the University of Innsbruck (UoI) in Austria, is one
of quantum computing’s pioneers and one of the most active researchers in this
field (quantum computing).
One of the
keys to opening the door to quantum computing is to make controllable qubits to
allow quantum properties to be exploited for information encoding and
processing. Already, in 2011, a team led by Rainer Blatt managed to create a
quantum register containing 14 controllable ultracold ions (qubits), a record
at the time.
Then, as we
reported last month, the Blatt team went even further and broke their own
record by creating a multi-particle entanglement system made of 20 addressable
and individually controllable qubits. Now, Prof. Blatt and his team at the
Institute for Quantum Optics and Quantum Information have made another
achievement that brings quantum entanglement even closer to practical
applications.
Toward
Ultra-Precise Quantum Instruments
After
acquiring the ability to generate and manipulate an entangled system and
individually address particles within it, Blatt’s team has now gone a step
further. This time, they found a way to control the light emission rate of a single photon in an entangled separated pair. The team worked on barium atoms
and investigated two scenarios where the particles are either entangled or not
entangled and compared the photon interference generated between the two cases.
Gabriel Araneda, a member of the research team, explained that: “The measurements showed that these are qualitatively different.
In fact, the measured difference of the interference fringes directly corresponds to the amount of entanglement in the atoms. In this way we can characterize the entanglement fully optically.”
The ability
to observe and control light emissions of entangled emitters (quantum
interference) would pave the way to the development of specific quantum
instruments with “previously unknown precision”.
“We take advantage of this sensitivity and use the observed interference signal to measure magnetic field gradients. This technique may lead to the development of ultra-sensitive optical gradiometers. As the measured effect does not rely on the proximity of the atoms, these measurements could allow to precisely comparing field strengths at separated locations, such as that of the Earth’s magnetic or gravitational fields,” said researchers.
Professor
Rainer Blatt and his team have been very successful in unlocking some secrets
of quantum entanglement, and this makes us excited as to what their next
research efforts could be.