Recently striking connections have been discovered between the research fields of black hole soultions in string theory and the one of entanglement measures in quantum entanglement theory.For the emerging research field the term The Black Hole/Qubit Correspondence has been coined. The basic idea is that wrapping configurations of extended objects in extra dimensions can give rise to interesting realizations of entangled systems and black holes at the same time. The geometry of the extra dimensions and the wrapping type determines the entangled system in question. Usually as the extra dimensional spaces Calabi-Yau manifolds are chosen. In this talk I give some hints how this constraint could be relaxed. These considerations might substantially generalize the range of validity of the Black-Hole/Qubit correspondence.
Two different branches of theoretical physics, string theory and quantum information theory (QIT), share many of the same features, allowing knowledge on one side to provide new insights on the other. In particular the matching of the classification of stringy black holes and the classification of four-qubit entanglement provides a falsifiable prediction in the field of QIT.
Space offers a very unique
environment for quantum physics experiments at regimes for distance and
velocity not possible on ground. In the recent years there have been a range of
theoretical and experimental studies towards the feasibility of performing
quantum physics and quantum information science experiments in space.
The most advanced quantum
application is quantum cryptography, known as quantum key distribution
(QKD), which can be extended to global distances by bringing suitable
quantum systems into space. It is interesting to note that with quantum
satellites in Earth's orbit, we will be able to perform tests on the validity
of quantum physics and entanglement at huge length scales and velocities. This
could provide a possible route towards gaining insights into the
interplay of quantum physics and relativity. I will review some of the
interesting quantum entanglement tests that can be performed with satellites in
space. I will also outline a proposed satellite mission that is based on
existing technology on a small-scale satellite, and could be a first important
step into this direction.
We will explore different results on relativistic quantum information and general relativistic quantum optics whose aim is to provide scenarios where relativistic quantum effects can be experimentally accessible. Traditionally, relativistic quantum information has been far away from the experimental test, but the discipline is close to the transition point where experimental outcomes will soon arise. Not only to bestow experimental proof on long ago predicted but still undetected phenomena (such as the Unruh and Hawking effects), but also to provide insight into the relationship of general relativity and quantum theory, and to serve as a source of new quantum technologies. We will show how it is possible to extract timelike and spacelike quantum correlations from the vacuum state of the field in a tabletop experiment, and how to use it to build a quantum memory. We will see how geometric phases can help to detect the Unruh effect and how to use what we learn from that setting to build a quantum thermometer. Finally we will discuss how quantum simulators can be applied to the study of quantum effects of gravity, and used to predict experimental scenarios way beyond current computational power of classical computers.
We
investigate entanglement creation between modes of a quantum field contained
within a cavity which undergoes noninertial motion. We find that, in the the low acceleration regime, or equivalently in the small
cavity regime, entanglement can be created from initially separable states and
it can be linearly increased by repeating travel scenarios. We are able to fin analytically how all the parameter involved affect the
entanglement. We suggest that this can be of interest when looking for
experimental veriications of predictions within the field of relativistic
quantum information.
Thought experiments involving quantum mechanics in the presence of closed time-like curves (CTCs) seem to have little to do with reality. However, even particles that traverse the CTC passively and without interactions can lead to highly non-trivial effects, such as the maximal violation of the uncertainty principle. Moreover, these effects may carry over to curved space-times without CTCs, presenting novel opportunities for testing non-standard physics in the relativistic regime.
I will discuss a new proposal with the potential to experimentally probe the validity of Rindler quantisation from the recent completely localized framework of non-inertial projective detectors of quantum fields.
We introduce a novel approach to measurements in QFT in non-inertial frames. A simple, localised, analytical model of state detection allows us to study all the standard questions of RQI and yielding simple answers with a clear physical interpretation. We apply the model to investigate extraction of the entanglement from the vacuum, completely characterize entangled state of two localised inertial wave-packets in the accelerating frame and study the entanglement degradation as a function of the proper acceleration of the detector.
Institute for Quantum Optics and Quantum Information (IQOQI) - Vienna
PIRSA:12060050
Experimental
tests of general relativity performed so far involve systems that can be
effectively described by classical physics. On the other hand, observed gravity
effects on quantum systems do not go beyond the Newtonian limit of the theory.
In light of the conceptual differences between general relativity and quantum
mechanics, as well as those of finding a unified theoretical framework for the
two theories, it is of particular interest to look for feasible experiments
that can only be explained if both theories apply.
We
propose testing general relativistic time dilation with a single “clock” in a
superposition of two paths in space-time, along which time flows at different
rates. We show that the interference visibility in such an experiment will
decrease to the extent to which the path information becomes available from
reading out the time from the “clock”. This effect would provide the first test
of the genuine general relativistic notion of time in quantum mechanics. We
consider implementation of the “clock” in evolving internal degrees of freedom
of a massive particle and, alternatively, in the external degree of a photon
and analyze the feasibility of the experiment.
While entanglement is believed to underlie the power of
quantum computation
and communication, it is not generally well understood
for multipartite
systems. Recently, it has been appreciated that there
exists proper
no-signaling probability distributions derivable from
operators that do not
represent valid quantum states. Such systems exhibit supra-correlations
that are stronger than allowed by quantum mechanics, but
less than the
algebraically allowed maximum in Bell-inequalities (in
the bipartite case).
Some of these probability distributions are derivable
from an entanglement
witness W, which is a non-positive Hermitian operator
constructed such that
its expectation value with a separable quantum state
(positive density
matrix) rho_sep is non-negative (so that Tr[W rho]< 0
indicates entanglement
in quantum state rho). In the bipartite case, it is known
that by a
modification of the local no-signaling measurements by
spacelike separated
parties A and B, the supra-correlations exhibited by any
W can be modeled as
derivable from a physically realizable quantum state ρ.
However, this result
does not generalize to the n-partite case for n>2.
Supra-correlations can
also be exhibited in 2- and 3-qubit systems by explicitly
constructing
"states" O (not necessarily positive quantum
states) that exhibit PR
correlations for a fixed, but arbitrary number, of
measurements available to
each party. In this paper we examine the structure of
"states" that exhibit
supra-correlations. In addition, we examine the affect
upon the distribution
of the correlations amongst the parties involved when
constraints of
positivity and purity are imposed. We investigate
circumstances in which
such "states" do and do not represent valid
quantum states.