3 research outputs found
Experimental Test of Quantum No-Hiding Theorem
Linearity and unitarity are two fundamental tenets of quantum theory. Any
consequence that follows from these must be respected in the quantum world. The
no-cloning theorem and the no-deleting theorem are the consequences of the
linearity and the unitarity. Together with the stronger no-cloning theorem they
provide permanence to quantum information, thus, suggesting that in the quantum
world information can neither be created nor be destroyed. In this sense
quantum information is robust, but at the same time it is also fragile because
any interaction with the environment may lead to loss of information. Recently,
another fundamental theorem was proved, namely, the no-hiding theorem that
addresses precisely the issue of information loss. It says that if any physical
process leads to bleaching of quantum information from the original system,
then it must reside in the rest of the universe with no information being
hidden in the correlation between these two subsystems. This has applications
in quantum teleportation, state randomization, private quantum channels,
thermalization and black hole evaporation. Here, we report experimental test of
the no-hiding theorem with the technique of nuclear magnetic resonance (NMR).
We use the quantum state randomization of a qubit as one example of the
bleaching process and show that the missing information can be fully recovered
up to local unitary transformations in the ancilla qubits. Since NMR offers a
way to test fundamental predictions of quantum theory using coherent control of
quantum mechanical nuclear spin states, our experiment is a step forward in
this direction.Comment: 12 pages, 6 Figs. Jharana Rani Samal, Deceased on her 27th birthday
12th Nov. 2009. The experimental work of this paper was completely carried
out by the first author. We dedicate this paper to the memory of the
brilliant soul of Ms. Jharana Rani Samal
Experimental Test of the Quantum No-Hiding Theorem
The no-hiding theorem says that if any physical process leads to bleaching of quantum information from the original system, then it must reside in the rest of the Universe with no information being hidden in the correlation between these two subsystems. Here, we report an experimental test of the no-hiding theorem with the technique of nuclear magnetic resonance. We use the quantum state randomization of a qubit as one example of the bleaching process and show that the missing information can be fully recovered up to local unitary transformations in the ancilla qubits
Non-destructive discrimination of Bell states by NMR using a single Ancilla qubit
Discrimination of Bell states plays an important role in a number of quantum computational protocols such as teleportation and secret sharing. However, most of the protocols dealing with Bell state discrimination in the literature either involve performing correlated measurements or destroying the entanglement of the system. Here, we demonstrate an NMR-based experimental realization of a protocol for Bell state discrimination, following a scheme proposed by Gupta et al (quant-ph/0504183v1, 23 April 2005), which does not destroy the Bell state under consideration. Using the proposed protocol, one can deterministically distinguish the Bell states, without performing a measurement using the entangled basis. State discrimination is performed through two independent measurements on one ancilla qubit, which leaves the Bell states unchanged