In this paper, we propose a quantum secret sharing protocol utilizing polarization modulated doubly entangled photon pairs. The measurement devices are constructed. By modulating the polarizations of entangled photons...In this paper, we propose a quantum secret sharing protocol utilizing polarization modulated doubly entangled photon pairs. The measurement devices are constructed. By modulating the polarizations of entangled photons, the boss could encode secret information on the initial state and share the photons with different members to realize the secret sharing process. This protocol shows the security against intercept-resend attack and dishonest member cheating. The generalized quantum secret sharing protocol is also discussed.展开更多
The long-range interaction between Rydberg-excited atoms endows a medium with large optical nonlinearity.Here,we demonstrate an optical switch to operate on a single photon from an entangled photon pair under a Rydber...The long-range interaction between Rydberg-excited atoms endows a medium with large optical nonlinearity.Here,we demonstrate an optical switch to operate on a single photon from an entangled photon pair under a Rydberg electromagnetically induced transparency configuration.With the presence of the Rydberg blockade effect,we switch on a gate field to make the atomic medium nontransparent thereby absorbing the single photon emitted from another atomic ensemble via the spontaneous fourwave mixing process.In contrast to the case without a gate field,more than 50%of the photons sent to the switch are blocked,and finally achieve an effective single-photon switch.There are on average 1-2 gate photons per effective blockade sphere in one gate pulse.This switching effect on a single entangled photon depends on the principal quantum number and the photon number of the gate field.Our experimental progress is significant in the quantum information process especially in controlling the interaction between Rydberg atoms and entangled photon pairs.展开更多
We investigate theoretically two photon entanglement processes in a photonic-crystal cavity embedding a quantum dot in tile strong-coupling regime. The model proposed by Johne et al. (Johne R, Gippius N A, Pavlovic G...We investigate theoretically two photon entanglement processes in a photonic-crystal cavity embedding a quantum dot in tile strong-coupling regime. The model proposed by Johne et al. (Johne R, Gippius N A, Pavlovic G, Solnyshkov D D, Shelykh I A and Malpuech G 2008 Phys. Rev. Lett. 100 240404), and by Robert et al. (Robert J, Gippius N A and Malpuech G 2009 Phys. Rev. B 79 155317) is modified by considering irreversible dissipation and incoherent continuous pumping for the quantum dot, which is necessary to connect the realistic experiment. The dynamics of tile system is analysed by employing the Born Markov master equation, through which the spectra for the system are computed as a fnnction of various parameters. By means of this analysis the photon-reabsorption process in the strong- coupling regime is first observed and analysed from the perspective of radiation spectrum and the optimal parameters for observing energy-entangled photon pairs are identified.展开更多
Semiconductor quantum dots are leading candidates for the on-demand generation of single photons and entangled photon pairs.High photon quality and indistinguishability of photons from different sources are critical f...Semiconductor quantum dots are leading candidates for the on-demand generation of single photons and entangled photon pairs.High photon quality and indistinguishability of photons from different sources are critical for quantum information applications.The inability to grow perfectly identical quantum dots with ideal optical properties necessitates the application of post-growth tuning techniques via e.g.temperature,electric,magnetic or strain fields.In this review,we summarize the state-of-the-art and highlight the advantages of strain tunable non-classical photon sources based on epitaxial quantum dots.Using piezoelectric crystals like PMN-PT,the wavelength of single photons and entangled photon pairs emitted by InGaAs/GaAs quantum dots can be tuned reversibly.Combining with quantum light-emitting diodes simultaneously allows for electrical triggering and the tuning of wavelength or exciton fine structure.Emission from light hole exciton can be tuned,and quantum dot containing nanostructure such as nanowires have been piezo-integrated.To ensure the indistinguishability of photons from distant emitters,the wavelength drift caused by piezo creep can be compensated by frequency feedback,which is verified by two-photon interference with photons from two stabilized sources.Therefore,strain tuning proves to be a flexible and reliable tool for the development of scalable quantum dots-based non-classical photon sources.展开更多
It is generally believed that nonorthogonal operations which can realize the state transformation between two nonorthogonal bases may ensure the security of many quantum communication protocols. However, in this paper...It is generally believed that nonorthogonal operations which can realize the state transformation between two nonorthogonal bases may ensure the security of many quantum communication protocols. However, in this paper, we present a powerful attack against quantum secret sharing protocols of these kinds. Applying entangled photons as fake signals, Eve can successfully steal the exact information without being revealed. We also give our effective modification to improve it. Under the suggested checking strategy, even to Eve's most general attack, it is robust and secure.展开更多
It is shown that the configuration of phase coding for quantum key distribution with single photon can also be used for continuous variable quantum key distribution. Therefore the robust long-distance high-speed quant...It is shown that the configuration of phase coding for quantum key distribution with single photon can also be used for continuous variable quantum key distribution. Therefore the robust long-distance high-speed quantum key distribution can be achieved with current technology.展开更多
Bell tests with entangled light have been performed many times in many ways using linear polarizers, but the same tests have never been done with a circular polarizer. Until recently there has never been a true circul...Bell tests with entangled light have been performed many times in many ways using linear polarizers, but the same tests have never been done with a circular polarizer. Until recently there has never been a true circular polarization beamsplitter—an optical component that separates light directly into left and right handed polarizations. Using a true circular polarization beamsplitter based on birefringent gratings, entangled light has been analyzed with unexpected results.展开更多
We put forward an optimal entanglement concentration protocol(ECP) for recovering an arbitrary less-entangled multi-photon Greenberger–Horne–Zeilinger(GHZ) state into the maximally entangled GHZ state based on t...We put forward an optimal entanglement concentration protocol(ECP) for recovering an arbitrary less-entangled multi-photon Greenberger–Horne–Zeilinger(GHZ) state into the maximally entangled GHZ state based on the photonic Faraday rotation in low-quality(Q) cavity. In the ECP, only one pair of less-entangled multi-photon GHZ state and one auxiliary photon are required, and the concentration task can be realized by local operations. Moreover, our ECP can be used repeatedly to further concentrate the discarded items of conventional ECPs, which can increase its success probability largely. Under the practical imperfect detection condition, our protocol can still work with relatively high success probability. This ECP has application potential in current and future quantum communication.展开更多
We propose schemes for the efficient information transfer between a propagating photon and a quantum-dot(QD) spin qubit in an optical microcavity that have no auxiliary particles required. With these methods, the in...We propose schemes for the efficient information transfer between a propagating photon and a quantum-dot(QD) spin qubit in an optical microcavity that have no auxiliary particles required. With these methods, the information transfer between two photons or two QD spins can also be achieved. All of our proposals can work with high fidelity, even with a high leakage rate. What is more, each information transfer process above can also be seen as a controlled-NOT(CNOT) operation. It is found that the information transfer can be equivalent to a CNOT gate. These proposals will promote more efficient quantum information networks and quantum computation.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10704010)
文摘In this paper, we propose a quantum secret sharing protocol utilizing polarization modulated doubly entangled photon pairs. The measurement devices are constructed. By modulating the polarizations of entangled photons, the boss could encode secret information on the initial state and share the photons with different members to realize the secret sharing process. This protocol shows the security against intercept-resend attack and dishonest member cheating. The generalized quantum secret sharing protocol is also discussed.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0304800)the National Natural Science Foundation of China(Grant Nos.61525504,61722510,61435011,11174271,61275115,and 11604322)+1 种基金the Anhui Initiative in Quantum Information Technologies(Grant No.AHY020200)the Youth Innovation Pro motion Association of Chinese Academy of Sciences(Grant No.2018490)。
文摘The long-range interaction between Rydberg-excited atoms endows a medium with large optical nonlinearity.Here,we demonstrate an optical switch to operate on a single photon from an entangled photon pair under a Rydberg electromagnetically induced transparency configuration.With the presence of the Rydberg blockade effect,we switch on a gate field to make the atomic medium nontransparent thereby absorbing the single photon emitted from another atomic ensemble via the spontaneous fourwave mixing process.In contrast to the case without a gate field,more than 50%of the photons sent to the switch are blocked,and finally achieve an effective single-photon switch.There are on average 1-2 gate photons per effective blockade sphere in one gate pulse.This switching effect on a single entangled photon depends on the principal quantum number and the photon number of the gate field.Our experimental progress is significant in the quantum information process especially in controlling the interaction between Rydberg atoms and entangled photon pairs.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2009AA03Z405)the National Natural Science Foundation of China (Grant Nos. 60908028, 60971068, and 10979065)+1 种基金the Program for New Century Excellent Talents in University (Grant No. NTCE-10-0261)the Chinese Universities Scientific Fund (Grant No. 2011RC0402)
文摘We investigate theoretically two photon entanglement processes in a photonic-crystal cavity embedding a quantum dot in tile strong-coupling regime. The model proposed by Johne et al. (Johne R, Gippius N A, Pavlovic G, Solnyshkov D D, Shelykh I A and Malpuech G 2008 Phys. Rev. Lett. 100 240404), and by Robert et al. (Robert J, Gippius N A and Malpuech G 2009 Phys. Rev. B 79 155317) is modified by considering irreversible dissipation and incoherent continuous pumping for the quantum dot, which is necessary to connect the realistic experiment. The dynamics of tile system is analysed by employing the Born Markov master equation, through which the spectra for the system are computed as a fnnction of various parameters. By means of this analysis the photon-reabsorption process in the strong- coupling regime is first observed and analysed from the perspective of radiation spectrum and the optimal parameters for observing energy-entangled photon pairs are identified.
基金financially supported by the ERC Starting Grant No.715770(QD-NOMS)the National Natural Science Foundation of China(No.61728501)
文摘Semiconductor quantum dots are leading candidates for the on-demand generation of single photons and entangled photon pairs.High photon quality and indistinguishability of photons from different sources are critical for quantum information applications.The inability to grow perfectly identical quantum dots with ideal optical properties necessitates the application of post-growth tuning techniques via e.g.temperature,electric,magnetic or strain fields.In this review,we summarize the state-of-the-art and highlight the advantages of strain tunable non-classical photon sources based on epitaxial quantum dots.Using piezoelectric crystals like PMN-PT,the wavelength of single photons and entangled photon pairs emitted by InGaAs/GaAs quantum dots can be tuned reversibly.Combining with quantum light-emitting diodes simultaneously allows for electrical triggering and the tuning of wavelength or exciton fine structure.Emission from light hole exciton can be tuned,and quantum dot containing nanostructure such as nanowires have been piezo-integrated.To ensure the indistinguishability of photons from distant emitters,the wavelength drift caused by piezo creep can be compensated by frequency feedback,which is verified by two-photon interference with photons from two stabilized sources.Therefore,strain tuning proves to be a flexible and reliable tool for the development of scalable quantum dots-based non-classical photon sources.
文摘It is generally believed that nonorthogonal operations which can realize the state transformation between two nonorthogonal bases may ensure the security of many quantum communication protocols. However, in this paper, we present a powerful attack against quantum secret sharing protocols of these kinds. Applying entangled photons as fake signals, Eve can successfully steal the exact information without being revealed. We also give our effective modification to improve it. Under the suggested checking strategy, even to Eve's most general attack, it is robust and secure.
基金Supported by the National Key Basic Research and Development Programme of China under Grant No 2001CB309300, the National Natural Science Foundation of China under Grant No 10304017, NCET, and the Knowledge Innovation Project from Chinese Academy of Sciences.
文摘It is shown that the configuration of phase coding for quantum key distribution with single photon can also be used for continuous variable quantum key distribution. Therefore the robust long-distance high-speed quantum key distribution can be achieved with current technology.
文摘Bell tests with entangled light have been performed many times in many ways using linear polarizers, but the same tests have never been done with a circular polarizer. Until recently there has never been a true circular polarization beamsplitter—an optical component that separates light directly into left and right handed polarizations. Using a true circular polarization beamsplitter based on birefringent gratings, entangled light has been analyzed with unexpected results.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474168 and 61401222)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20151502)+1 种基金the Qing Lan Project of Jiangsu Province,Chinaa Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We put forward an optimal entanglement concentration protocol(ECP) for recovering an arbitrary less-entangled multi-photon Greenberger–Horne–Zeilinger(GHZ) state into the maximally entangled GHZ state based on the photonic Faraday rotation in low-quality(Q) cavity. In the ECP, only one pair of less-entangled multi-photon GHZ state and one auxiliary photon are required, and the concentration task can be realized by local operations. Moreover, our ECP can be used repeatedly to further concentrate the discarded items of conventional ECPs, which can increase its success probability largely. Under the practical imperfect detection condition, our protocol can still work with relatively high success probability. This ECP has application potential in current and future quantum communication.
基金the financial support from the National Natural Science Foundation of China(11774326)the National Key R&D Program of China(2017YFA0304301)+2 种基金Innovation Program for Quantum Science and Technology(2021ZD0300204)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)Anhui Initiative in Quantum Information Technologies。
基金supported by the National Natural Science Foundation of China under Grants Nos.61275059 and 61307062
文摘We propose schemes for the efficient information transfer between a propagating photon and a quantum-dot(QD) spin qubit in an optical microcavity that have no auxiliary particles required. With these methods, the information transfer between two photons or two QD spins can also be achieved. All of our proposals can work with high fidelity, even with a high leakage rate. What is more, each information transfer process above can also be seen as a controlled-NOT(CNOT) operation. It is found that the information transfer can be equivalent to a CNOT gate. These proposals will promote more efficient quantum information networks and quantum computation.