Entanglement-assisted scheme for nondemolition detection of the presence of a single photon

Bula, Marek; Bartkiewicz, Karol; Cernoch, A; Lemr, Karel

doi:10.1103/physreva.87.033826

Cited by 22 publications

(27 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this particular case, it is however possible to increase the success probability twice by including also detection coincidences DA and AD accompanied by a feed-forward operation V → −V on the output state. Note that this regime is suitable for non-demolition presence detection of the qubit [22]. Fig.…”

Section: Principle Of Operationmentioning

confidence: 96%

Entanglement-based linear-optical qubit amplifier

et al. 2013

Self Cite

View full text Add to dashboard Cite

We propose a linear-optical scheme for an efficient amplification of a photonic qubit based on interaction of the signal mode with a pair of entangled ancillae. In contrast to a previous proposal for qubit amplifier by Gisin et al., [Phys Rev. Lett. 105, 070501 (2010)] the success probability of our device does not decrease asymptotically to zero with increasing gain. Moreover we show how the device can be used to restore entanglement deteriorated by transmission over a lossy channel and calculate the secure key rate for device-independent quantum key distribution.

show abstract

Section: Principle Of Operationmentioning

confidence: 96%

Entanglement-based linear-optical qubit amplifier

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…[36]). Finally, the nondemolition presence detection can be achieved with the assistance o f two ancillas [41] in the polarization singlet state. The method is successful if there are two photons registered by each pair of the photon-number-resolving detectors D\, £>3 , and £)4, while one photon is detected by either D)1 or £>('.…”

Section: Proposal Of Experimental Implementationmentioning

confidence: 99%

“…The idea behind the method is to use two quantum gates: the controlled-NOT (CNOT) gate [36][37][38][39] and the exclusive OR (XOR) gate [40]. In order to join two CNOT gates, it is also required to introduce the nondemolition photon presence detection gate, which uses two additional ancillas in a Bell state [41,42]. By heralding the presence of a qubit, this gate informs that the preceding CNOT operation was successful.…”

Section: A Alternative Setup For Measuring Ii4mentioning

confidence: 99%

Method for universal detection of two-photon polarization entanglement

et al. 2015

Self Cite

View full text Add to dashboard Cite

Detecting and quantifying quantum entanglement of a given unknown state poses problems that are fundamentally important for quantum information processing. Surprisingly, no direct (i.e., without quantum tomography) universal experimental implementation of a necessary and sufficient test of entanglement has been designed even for a general two-qubit state. Here we propose an experimental method for detecting a collective universal witness, which is a necessary and sufficient test of two-photon polarization entanglement. It allows us to detect entanglement for any two-qubit mixed state and to establish tight upper and lower bounds on its amount. A different element of this method is the sequential character of its main components, which allows us to obtain relatively complicated information about quantum correlations with the help of simple linear-optical elements. As such, this proposal realizes a universal two-qubit entanglement test within the present state of the art of quantum optics. We show the optimality of our setup with respect to the minimal number of measured quantities.Comment: 7 pages, 5 figure

show abstract

“…However, the latter approach would be much more difficult to implement because it would require a nondemolition photon-presence detection (see, e.g., Ref. [38]). In the former approach, we assume that the state preparation governed by the probability distribution P (a|A) is equivalent to Alice's nondestructive equiprobable measurements of A i = σ i for i = 1, 2, 3, where the outcomes of the measurement A i are a = ±1 and appear with the probability P (a|A i ) = 1/2.…”

mentioning

confidence: 99%

Experimental temporal quantum steering

Bartkiewicz

Cernoch

Lemr

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Temporal steering is a form of temporal correlation between the initial and final state of a quantum system. It is a temporal analogue of the famous Einstein-Podolsky-Rosen (spatial) steering. We demonstrate, by measuring the photon polarization, that temporal steering allows two parties to verify if they have been interacting with the same particle, even if they have no information about what happened with the particle in between the measurements. This is the first experimental study of temporal steering. We also performed experimental tests, based on the violation of temporal steering inequalities, of the security of two quantum key distribution protocols against individual attacks. Thus, these results can lead to applications for secure quantum communications and quantum engineering.Einstein-Podolsky-Rosen (EPR) steering refers to strong nonclassical nonlocal bipartite correlations. It was first described by Schrödinger 1 as a generalization of the EPR paradox 2 . The recent celebration of the 80 years of steering and the EPR paradox 3 showed that our understanding of this phenomenon is now much deeper, but still very limited. Steering differs from quantum entanglement 4 and Bell nonlocality 5-7 , as not every entangled state manifests steering and not every state that manifests steering violates Bell's inequality 8 . In other words, steerable states are a subset of entangled states and a superset of Bell nonlocal states. Analogously to Bell nonlocality, steering can be detected independently of other nonclassical correlations by simple inequalities [8][9][10] that can include as little as two measurements with two outcomes for Alice and a set of four possible states for Bob 9 . Such inequalities were tested in several experiments [10][11][12][13][14][15][16][17] , including a recent loophole-free experiment 18 . Steering can be interpreted as a correlation between two systems (measuring devices), where only one of them is trusted. This property shows an operational meaning of steering and indicates its potential applications in quantum cryptography and quantum communication, e.g., for entanglement distribution 8,19 . Steering-based protocols can provide secure communications even when only one party trusts its devices. Such protocols are easier to implement than completely-device-independent protocols 20 , but are more secure than standard protocols requiring mutual trust between the communicating parties.Temporal steering 21 (TS), analogously to EPR steering, is observed when Alice can steer Bob's state into one of two orthogonal states by properly choosing her measured observable. Despite this similarity, the implications of these temporal and spatial phenomena are fundamentally different. To detect TS 21 , Alice and Bob perform consecutive measurements (using a random sequence of mutually-unbiased bases known only to them) on the same system to test temporal correlations between its initial and final states. Breaking the temporal steering inequality, given in ref. 21, implies that no unauthorised party ca...

show abstract

Entanglement-assisted scheme for nondemolition detection of the presence of a single photon

Cited by 22 publications

References 41 publications

Entanglement-based linear-optical qubit amplifier

Entanglement-based linear-optical qubit amplifier

Method for universal detection of two-photon polarization entanglement

Experimental temporal quantum steering

Contact Info

Product

Resources

About