Two-party QPC with polarization-entangled Bell states and the coherent states

2014 ◽  
Vol 14 (3&4) ◽  
pp. 236-254
Author(s):  
Xiao-Ming Xiu ◽  
Li Dong ◽  
Hong-Zhi Shen ◽  
Ya-Jun Gao ◽  
X. X. Yi

We propose a protocol of quantum privacy comparison with polarization-entangled Einstein-Podolsky-Rosen (Bell) states and the coherent states. One of two legitimate participants, Alice, prepares polarization-entangled Bell states and keeps one photon of each photon pair and sends the other photons to the third party, Charlie. Receiving the photons, Charlie performs single-photon transformation operations on them and then sends them to the other legitimate participant, Bob. Three participants adopt parity analysis method to check the distribution security of Bell states. Exploiting polarization beam splitters and nonlinear interactions mediated by the probe coherent states in Kerr media, Alice and Bob check the parities of their photons using the bases of $\{\ket H, \ket V\}$ or $\{\ket +, \ket -\}$. On the basis of the parity analysis outcomes and Charlie's publicized information, they can analyze the security of the distributed quantum channel. Confirming secure distribution of the shared Bell states, two participants perform respective parity measurements on the privacy photons and own photons of Bell states, and then send the results to Charlie. According to information provided by two legitimate participants and his single-qubit transformation operations, Charlie compares the privacy information of Alice and Bob and publicizes the conclusion.

2013 ◽  
Vol 11 (07) ◽  
pp. 1350064
Author(s):  
LI DONG ◽  
JUN-XI WANG ◽  
XIAO-MING XIU ◽  
HAI-KUAN DONG ◽  
DAN LI ◽  
...  

We propose a scheme for preparing the distributed four-photon cluster-type polarization-entangled states associated with the integration of the controlled phase gate and two kinds of entanglement gates. Employing weak cross-Kerr nonlinear interactions and Homodyne measurement, two individual photons entangle together based on the bus function of coherent states. Assisted by optical elements mainly including polarization beam splitters, the entanglement of the signal photons is converted from the spatial mode to the polarization mode. The application of classical feed forward provides the high-efficiency to the preparation of Einstein–Podolsky–Rosen (EPR) states, Greenberger–Horne–Zeilinger (GHZ) states, and four-photon cluster-type polarization-entangled states. With regard to the four-photon cluster-type state, it can be generated in two distributed nodes with less experimental requirements, integrating the features of three logical gates.


2020 ◽  
Vol 8 (1) ◽  
pp. 78
Author(s):  
Dija Hedistira ◽  
' Pujiyono

<p>Abstract<br />This article aims to analyze the ownership and mastery of a fiduciary collateral object, in cases that often occur today, many disputes between creditors and debtors in fiduciary collateral agreements are caused because creditors assume that with executive rights as fiduciary recipients, the fiduciary collateral object legally owned by creditors and creditors the right to take and sell fiduciary collateral objects when the debtor defaults unilaterally, as well as the debtor who considers that the fiduciary collateral object is owned by him because the object is registered on his name, so that the debtor can use the object free as  giving to a third party or selling the object of fiduciary guarantee unilaterally. the author uses a normative <br />juridical approach, and deductive analysis method based on the Civil Code and fiduciary law applicable in Indonesia, Law No. 42 of 1999 concerning Fiduciary Guarantees. The conclusion of the discussion is the ownership of the object of the Fiduciary Guarantee is owned by the debtor in accordance with the Law, mastery of the object of collateral controlled by the debtor for economic benefits, the procedure of execution The object of Fiduciary Guarantee is carried out in accordance with the Fiduciary Guarantee Act, an alternative mediation in resolving the dispute. There needs to be clarity in the use of language in making a law, so as not to conflict with each other between Article one and the other Articles.<br />Keywords: Ownership; Mastery; Object of Fiduciary Guarantee; Debtor; Creditors.</p><p>Abstrak<br />Artikel ini bertujuan untuk menganalisis tentang kepemilikan dan penguasaan suatu objek jaminan fidusia, dalam kasus yang saat ini sering terjadi, banyak sengketa antara kreditur dan debitur dalam perjanjian jaminan fidusia disebabkan karena kreditur beranggapan bahwa dengan adanya hak eksekutorial sebagai penerima fidusia, maka objek jaminan fidusia tersebut secara sah dimiliki oleh kreditur dan kreditur berhak mengambil dan menjual objek jaminan fidusia saat debitur cidera janji<br />(wanprestasi) secara sepihak, begitupun dengan debitur yang menganggap bahwa objek jaminan fidusia tersebut dimiliki olehnya karena objek tersebut terdaftar atas namannya, sehingga debitur dapat mempergunakan objek tersebut secara bebas seperti menyerahkan kepada pihak ketiga atau menjual objek jaminan fidusia tersebut secara sepihak. penulis menggunakan pendekatan yuridis normatif, dan metode analisis deduktif yang didasarkan pada Kitab Undang-Undang Hukum Perdata<br />dan hukum jaminan fidusia yang berlaku di Indonesia, Undang-Undang No. 42 Tahun 1999 tentang Jaminan Fidusia. Kesimpulan pembahasan adalah Kepemilikan Objek Jaminan Fidusia dimiliki oleh debitur sesuai Undang-undang, penguasaan objek jaminan dikuasai debitur untuk manfaat ekonomis, prosedur eksekusi Objek Jaminan Fidusia dilakukan sesuai dengan Undang-Undang Jaminan Fidusia, alternatif secara mediasi dalam menyelesaikan sengketa yang terjadi. Perlu ada kejelasan dalam<br />penggunaan bahasa pada pembuatan suatu Undang-Undang, agar tidak saling bertentangan antar Pasal satu dengan Pasal yang lainnya. <br />Kata Kunci: Kepemilikan; Penguasaan; Objek Jaminan Fidusia; Debitur; Kreditur.</p>


2011 ◽  
Vol 11 (1&2) ◽  
pp. 124-141
Author(s):  
Nguyen B. An ◽  
Kisik Kim ◽  
Jaewan Kim

We propose a scheme to generate a recently introduced type of entangled coherent states using realistic weak cross-Kerr nonlinearities and intense laser beams. An intense laser can be filtered to make a faint one to be used for production of a single photon which is necessary in our scheme. The optical devices used are conventional ones such as interferometer, mirrors, beam-splitters, phase-shifters and photo-detectors. We also provide a detailed analysis on the effects of possible imperfections and decoherence showing that our scheme is robust against such effects.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Qingle Wang ◽  
Yami Fang ◽  
Xiaoping Ma ◽  
Dong Li

AbstractWe theoretically analyze the phase sensitivity of an $\operatorname{SU}(1,1)$ SU ( 1 , 1 ) interferometer with various input states by product detection in this paper. This interferometer consists of two parametric amplifiers that play the role of beam splitters in a traditional Mach–Zehnder interferometer. The product of the amplitude quadrature of one output mode and the momentum quadrature of the other output mode is measured via balanced homodyne detection. We show that product detection has the same phase sensitivity as parity detection for most cases, and it is even better in the case with two coherent states at the input ports. The phase sensitivity is also compared with the Heisenberg limit and the quantum Cramér–Rao bound of the $\operatorname{SU}(1,1)$ SU ( 1 , 1 ) interferometer. This detection scheme can be easily implemented with current homodyne technology, which makes it highly feasible. It can be widely applied in the field of quantum metrology.


2021 ◽  
Author(s):  
A. V. Kozubov ◽  
A. A. Gaidash ◽  
A. D. Kiselev ◽  
G. P. Miroshnichenko

Abstract In this paper we present the approach to complete Bell state analysis based on filtering mapping. The key distinctive feature of this appoach is that it avoids complications related to using either hyperentanglement or representation of the Bell states as concatenated Greenber–Horne–Zeilinger (C-GHZ) state to perform discrimination procedure. We describe two techniques developed within the suggested approach and based on two-step algorithms with two different types of filtration mapping which can be called the non-demolition and semi-demolition filtrations. In the method involving non-demolition filtration measurement the filtration process employs cross-Kerr nonlinearity and the probe mode to distinguish between the two pairs of the Bell states. In the case of semi-demolition measurement, the two states are unambiguously discriminated and hence destroyed, whereas filtraton keeps the other two states intact. We show that the measurement that destroys the single photon subspace in every mode and preserves the superposition of zero and two photons can be realized with discrete photodetection based on microresonator with atoms.


2002 ◽  
Vol 2 (3) ◽  
pp. 208-221
Author(s):  
H. Jeong ◽  
M.S. Kim

We suggest an entanglement purification scheme for mixed entangled coherent states using 50-50 beam splitters and photodetectors. This scheme is directly applicable for mixed entangled coherent states of the Werner type, and can be useful for general mixed states using additional nonlinear interactions. We apply our scheme to entangled coherent states decohered in a vacuum environment and find the decay time until which they can be purified.


2005 ◽  
Vol 03 (03) ◽  
pp. 555-560 ◽  
Author(s):  
ZHAN-JUN ZHANG ◽  
ZHONG-XIAO MAN ◽  
SHOU-HUA SHI

We propose a quantum key distribution (QKD) scheme in which four parties can simultaneously share a secret key via optical device. The participants divide the communication into two modes, namely, detecting mode and message mode. Taking advantage of controlled secret short key technology, the participants together can achieve the detecting mode or the message mode by switching between their two sets of optical devices. In the detecting mode, the key distributer Alice utilizes a single-photon state resource and two beam splitters and the other three participants Bob, Charlie and Dick use first-type devices to detect the superposition of vacuum and single-particle states. Hence, any eavesdropping can be found by using a variant of Bell's inequality. In the message mode, Alice uses a two-photon Bell-state resource and two polarization beam splitters instead of the single-particle state resource and beam splitters used in the detecting mode and the other three participants use second-type devices to detect photons. In this case, the secret key can be successfully distributed from Alice to the other three ones. Moreover, the present four-party QKD scheme can be generalized to a 2n-party QKD scheme by using n-photon Greenberg–Horne–Zeilinger.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. V. Kozubov ◽  
A. A. Gaidash ◽  
A. D. Kiselev ◽  
G. P. Miroshnichenko

AbstractIn this paper, we present the approach to complete Bell state analysis based on filtering mapping. The key distinctive feature of this appoach is that it avoids complications related to using either hyperentanglement or representation of the Bell states as concatenated Greenber–Horne–Zeilinger (C-GHZ) state to perform discrimination procedure. We describe two techniques developed within the suggested approach and based on two-step algorithms with two different types of filtration mapping which can be called the non-demolition and semi-demolition filtrations. In the method involving non-demolition filtration measurement the filtration process employs cross-Kerr nonlinearity and the probe mode to distinguish between the two pairs of the Bell states. In the case of semi-demolition measurement, the two states are unambiguously discriminated and hence destroyed, whereas filtraton keeps the other two states intact. We show that the measurement that destroys the single photon subspace in every mode and preserves the superposition of zero and two photons can be realized with discrete photodetection based on microresonator with atoms.


2004 ◽  
Vol 9 (3) ◽  
pp. 233-240 ◽  
Author(s):  
S. Kim

This paper describes a Voronoi analysis method to analyze a soccer game. It is important for us to know the quantitative assessment of contribution done by a player or a team in the game as an individual or collective behavior. The mean numbers of vertices are reported to be 5–6, which is a little less than those of a perfect random system. Voronoi polygons areas can be used in evaluating the dominance of a team over the other. By introducing an excess Voronoi area, we can draw some fruitful results to appraise a player or a team rather quantitatively.


2017 ◽  
Vol 2 (2) ◽  
pp. 155-168 ◽  
Author(s):  
David Wong

This research aims at analyzing (1) the effect of vendor’s ability, benevolence, and integrity variables toward e-commerce customers’ trust in UBM; (2) the effect of vendor’s ability, benevolence, and integrity variables toward the level of e-commerce customers’ participation in Indonesia; and (3) the effect of trust variable toward level of e-commerce customers participation in UBM. This research makes use of UBM e-commerce users as research samples while using Likert scale questionnaire for data collection. Furthermore, the questionnaires are sent to as many as 200 respondents. For data analysis method, Structural Equation Model was used. Out of three predictor variables (ability, benevolence, and integrity), it is only vendor’s integrity that has a positive and significant effect on customers’ trust. On the other hand, it is only vendor’s integrity and customer’s trust that have a positive and significant effect on e-commerce customers’ participation in UBM. Keywords: e-commerce customers’ participation, ability, benevolence, integrity


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