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Stephan Ritter - One of the best experts on this subject based on the ideXlab platform.
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photon mediated Quantum Gate between two neutral atoms in an optical cavity
Physical Review X, 2018Co-Authors: Stephan Welte, Stephan Ritter, Bastian Hacker, Severin Daiss, Gerhard RempeAbstract:Quantum communication requires the ability for network nodes to send and receive photons as well as process Quantum information. New experiments demonstrate just such a Quantum Gate, realized by two neutral atoms coupled by an optical photon.
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a photon photon Quantum Gate based on a single atom in an optical resonator
Nature, 2016Co-Authors: Bastian Hacker, Gerhard Rempe, Stephan Welte, Stephan RitterAbstract:To enable two photons to interact, a single atom in an optical resonator is used to build a universal photon–photon Quantum Gate; this could lead to applications in long-distance Quantum communication and scalable Quantum computing that require the processing of optical Quantum information. Two beams of light sharing the same space tend not to interact with one another. Yet if purely photonic technologies such as Quantum communication and scalable Quantum computing are to be developed — which require components such as switches and logic Gates — it will be important to find conditions that facilitate controllable interactions between two photons. To that end, various single-photon Quantum devices have been demonstrated in recent years, typically involving interactions between photons and atoms in a resonator. Here Stephan Ritter and colleagues employ such a system to make a logic component for Quantum operations — a universal controlled phase flip photon–photon Quantum Gate — that involves interaction between two individual input photons mediated by a single atom. That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical Quantum information processing1. The long-standing challenge here is to realize a deterministic photon–photon Gate, that is, a mutually controlled logic operation on the Quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other’s phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon’s polarization to an orthogonal state. So far, only probabilistic Gates2 based on linear optics and photon detectors have been realized3, because “no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift”4. Meanwhile, tremendous progress in the development of Quantum-nonlinear systems has opened up new possibilities for single-photon experiments5. Platforms range from Rydberg blockade in atomic ensembles6 to single-atom cavity Quantum electrodynamics7. Applications such as single-photon switches8 and transistors9,10, two-photon Gateways11, nondestructive photon detectors12, photon routers13 and nonlinear phase shifters14,15,16,17,18 have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light–matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan–Kimble protocol19 of a universal controlled phase flip (π phase shift) photon–photon Quantum Gate. We achieve an average Gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon–photon Quantum Gate is a universal Quantum logic element, and therefore could perform most existing two-photon operations. The demonstrated feasibility of deterministic protocols for the optical processing of Quantum information could lead to new applications in which photons are essential, especially long-distance Quantum communication and scalable Quantum computing.
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a Quantum Gate between a flying optical photon and a single trapped atom
Nature, 2014Co-Authors: Andreas Reiserer, N Kalb, Gerhard Rempe, Stephan RitterAbstract:Quantum Gates — in which stationary Quantum bits are combined with ‘flying’ Quantum bits, that is, photons — will be essential in Quantum networks; such a Gate, between a laser-trapped atomic Quantum bit and a single photon, is now reported. The development of a Quantum Gate between a flying optical photonic qubit (polarization) and a single trapped atomic qubit (spin) has been a long-standing goal in Quantum information science. Such Gates are required both for Quantum computation to be scaled to a large number of qubits and for Quantum communication to be scaled to long distances. Now two groups, working independently, report the successful implementation of such Gates. Gerhard Rempe and colleagues demonstrate a Quantum Gate between a laser-trapped atomic qubit and a single photon, where the polarization of the photon is flipped depending exactly on the spin state of the atom. Mikhail Lukin and co-workers describe a similar achievement — a Quantum Gate effect between a single atom trapped near a photonic crystal and a single photon. The steady increase in control over individual Quantum systems supports the promotion of a Quantum technology that could provide functionalities beyond those of any classical device. Two particularly promising applications have been explored during the past decade: photon-based Quantum communication, which guarantees unbreakable encryption1 but which still has to be scaled to high rates over large distances, and Quantum computation, which will fundamentally enhance computability2 if it can be scaled to a large number of Quantum bits (qubits). It was realized early on that a hybrid system of light qubits and matter qubits3 could solve the scalability problem of each field—that of communication by use of Quantum repeaters4, and that of computation by use of an optical interconnect between smaller Quantum processors5,6. To this end, the development of a robust two-qubit Gate that allows the linking of distant computational nodes is “a pressing challenge”6. Here we demonstrate such a Quantum Gate between the spin state of a single trapped atom and the polarization state of an optical photon contained in a faint laser pulse. The Gate mechanism presented7,8 is deterministic and robust, and is expected to be applicable to almost any matter qubit. It is based on reflection of the photonic qubit from a cavity that provides strong light–matter coupling. To demonstrate its versatility, we use the Quantum Gate to create atom–photon, atom–photon–photon and photon–photon entangled states from separable input states. We expect our experiment to enable various applications, including the generation of atomic9 and photonic10 cluster states and Schrodinger-cat states11, deterministic photonic Bell-state measurements12, scalable Quantum computation7 and Quantum communication using a redundant Quantum parity code13.
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a Quantum Gate between a flying optical photon and a single trapped atom
Nature, 2014Co-Authors: Andreas Reiserer, N Kalb, Gerhard Rempe, Stephan RitterAbstract:After demonstration of the conditional phase shift mechanism in Reiserer et al. (Science 342(6164):1349–1351, 2013), it was also applied to demonstrate an atom-photon Quantum Gate, which is described in the following.
Gerhard Rempe - One of the best experts on this subject based on the ideXlab platform.
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a photon photon Quantum Gate based on rydberg interactions
Nature Physics, 2019Co-Authors: Daniel Tiarks, Gerhard Rempe, Steffen Schmidteberle, Thomas Stolz, Stephan DurrAbstract:The interaction between Rydberg states of neutral atoms is strong and long-range, making it appealing to put it to use in the context of Quantum technologies. Recently, first applications of this idea have been reported in the fields of Quantum computation1 and Quantum simulation2–4. Furthermore, electromagnetically induced transparency allows one to map these Rydberg interactions to light5–15. Here we exploit this mapping and the resulting interaction between photons to realize a photon–photon Quantum Gate16,17, demonstrating the potential of Rydberg systems as a platform also for Quantum communication and Quantum networking18. We measure a controlled-NOT truth table with a fidelity of 70(8)% and an entangling-Gate fidelity of 63.7(4.5)%, both post-selected upon detection of a control and a target photon. The level of control reached here is an encouraging step towards exploring novel many-body states of photons or for future applications in Quantum communication and Quantum networking18. Strong and long-range interactions between Rydberg states of neutral atoms can be mapped to light via electromagnetically induced transparency, realizing a photon–photon Quantum Gate for Quantum communications and networking.
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a photon photon Quantum Gate based on rydberg interactions
arXiv: Quantum Physics, 2018Co-Authors: Daniel Tiarks, Gerhard Rempe, Steffen Schmidteberle, Thomas Stolz, Stephan DurrAbstract:The interaction between Rydberg states of neutral atoms is strong and long-range, making it appealing to put it to use in the context of Quantum technologies. Recently, first applications of this idea have been reported in the fields of Quantum computation and Quantum simulation. Furthermore, electromagnetically induced transparency allows to map these Rydberg interactions to light. Here we exploit this mapping and the resulting interaction between photons to realize a photon-photon Quantum Gate, demonstrating the potential of Rydberg systems as a platform also for Quantum communication and Quantum networking. We measure a controlled-NOT truth table with a fidelity of 70(8)% and an entangling-Gate fidelity of 63.7(4.5)%, both post-selected upon detection of a control and a target photon. The level of control reached here is an encouraging step towards exploring novel many-body states of photons or for future applications in Quantum communication and Quantum networking.
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photon mediated Quantum Gate between two neutral atoms in an optical cavity
Physical Review X, 2018Co-Authors: Stephan Welte, Stephan Ritter, Bastian Hacker, Severin Daiss, Gerhard RempeAbstract:Quantum communication requires the ability for network nodes to send and receive photons as well as process Quantum information. New experiments demonstrate just such a Quantum Gate, realized by two neutral atoms coupled by an optical photon.
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a photon photon Quantum Gate based on a single atom in an optical resonator
Nature, 2016Co-Authors: Bastian Hacker, Gerhard Rempe, Stephan Welte, Stephan RitterAbstract:To enable two photons to interact, a single atom in an optical resonator is used to build a universal photon–photon Quantum Gate; this could lead to applications in long-distance Quantum communication and scalable Quantum computing that require the processing of optical Quantum information. Two beams of light sharing the same space tend not to interact with one another. Yet if purely photonic technologies such as Quantum communication and scalable Quantum computing are to be developed — which require components such as switches and logic Gates — it will be important to find conditions that facilitate controllable interactions between two photons. To that end, various single-photon Quantum devices have been demonstrated in recent years, typically involving interactions between photons and atoms in a resonator. Here Stephan Ritter and colleagues employ such a system to make a logic component for Quantum operations — a universal controlled phase flip photon–photon Quantum Gate — that involves interaction between two individual input photons mediated by a single atom. That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical Quantum information processing1. The long-standing challenge here is to realize a deterministic photon–photon Gate, that is, a mutually controlled logic operation on the Quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other’s phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon’s polarization to an orthogonal state. So far, only probabilistic Gates2 based on linear optics and photon detectors have been realized3, because “no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift”4. Meanwhile, tremendous progress in the development of Quantum-nonlinear systems has opened up new possibilities for single-photon experiments5. Platforms range from Rydberg blockade in atomic ensembles6 to single-atom cavity Quantum electrodynamics7. Applications such as single-photon switches8 and transistors9,10, two-photon Gateways11, nondestructive photon detectors12, photon routers13 and nonlinear phase shifters14,15,16,17,18 have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light–matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan–Kimble protocol19 of a universal controlled phase flip (π phase shift) photon–photon Quantum Gate. We achieve an average Gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon–photon Quantum Gate is a universal Quantum logic element, and therefore could perform most existing two-photon operations. The demonstrated feasibility of deterministic protocols for the optical processing of Quantum information could lead to new applications in which photons are essential, especially long-distance Quantum communication and scalable Quantum computing.
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a Quantum Gate between a flying optical photon and a single trapped atom
Nature, 2014Co-Authors: Andreas Reiserer, N Kalb, Gerhard Rempe, Stephan RitterAbstract:Quantum Gates — in which stationary Quantum bits are combined with ‘flying’ Quantum bits, that is, photons — will be essential in Quantum networks; such a Gate, between a laser-trapped atomic Quantum bit and a single photon, is now reported. The development of a Quantum Gate between a flying optical photonic qubit (polarization) and a single trapped atomic qubit (spin) has been a long-standing goal in Quantum information science. Such Gates are required both for Quantum computation to be scaled to a large number of qubits and for Quantum communication to be scaled to long distances. Now two groups, working independently, report the successful implementation of such Gates. Gerhard Rempe and colleagues demonstrate a Quantum Gate between a laser-trapped atomic qubit and a single photon, where the polarization of the photon is flipped depending exactly on the spin state of the atom. Mikhail Lukin and co-workers describe a similar achievement — a Quantum Gate effect between a single atom trapped near a photonic crystal and a single photon. The steady increase in control over individual Quantum systems supports the promotion of a Quantum technology that could provide functionalities beyond those of any classical device. Two particularly promising applications have been explored during the past decade: photon-based Quantum communication, which guarantees unbreakable encryption1 but which still has to be scaled to high rates over large distances, and Quantum computation, which will fundamentally enhance computability2 if it can be scaled to a large number of Quantum bits (qubits). It was realized early on that a hybrid system of light qubits and matter qubits3 could solve the scalability problem of each field—that of communication by use of Quantum repeaters4, and that of computation by use of an optical interconnect between smaller Quantum processors5,6. To this end, the development of a robust two-qubit Gate that allows the linking of distant computational nodes is “a pressing challenge”6. Here we demonstrate such a Quantum Gate between the spin state of a single trapped atom and the polarization state of an optical photon contained in a faint laser pulse. The Gate mechanism presented7,8 is deterministic and robust, and is expected to be applicable to almost any matter qubit. It is based on reflection of the photonic qubit from a cavity that provides strong light–matter coupling. To demonstrate its versatility, we use the Quantum Gate to create atom–photon, atom–photon–photon and photon–photon entangled states from separable input states. We expect our experiment to enable various applications, including the generation of atomic9 and photonic10 cluster states and Schrodinger-cat states11, deterministic photonic Bell-state measurements12, scalable Quantum computation7 and Quantum communication using a redundant Quantum parity code13.
Andreas Reiserer - One of the best experts on this subject based on the ideXlab platform.
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a controlled phase Gate between a single atom and an optical photon
2015Co-Authors: Andreas ReisererAbstract:A single rubidium atom is trapped in an optical lattice at the center of an optical cavity in the strong coupling regime. When a photon contained in a faint laser pulse is reflected from the resonator, the combined atom-photon state acquires a state-dependent phase shift. This allows to non-destructively detect optical photons and to implement a universal Quantum Gate between the atom and one or two successively reflected photons.
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a Quantum Gate between a flying optical photon and a single trapped atom
Nature, 2014Co-Authors: Andreas Reiserer, N Kalb, Gerhard Rempe, Stephan RitterAbstract:Quantum Gates — in which stationary Quantum bits are combined with ‘flying’ Quantum bits, that is, photons — will be essential in Quantum networks; such a Gate, between a laser-trapped atomic Quantum bit and a single photon, is now reported. The development of a Quantum Gate between a flying optical photonic qubit (polarization) and a single trapped atomic qubit (spin) has been a long-standing goal in Quantum information science. Such Gates are required both for Quantum computation to be scaled to a large number of qubits and for Quantum communication to be scaled to long distances. Now two groups, working independently, report the successful implementation of such Gates. Gerhard Rempe and colleagues demonstrate a Quantum Gate between a laser-trapped atomic qubit and a single photon, where the polarization of the photon is flipped depending exactly on the spin state of the atom. Mikhail Lukin and co-workers describe a similar achievement — a Quantum Gate effect between a single atom trapped near a photonic crystal and a single photon. The steady increase in control over individual Quantum systems supports the promotion of a Quantum technology that could provide functionalities beyond those of any classical device. Two particularly promising applications have been explored during the past decade: photon-based Quantum communication, which guarantees unbreakable encryption1 but which still has to be scaled to high rates over large distances, and Quantum computation, which will fundamentally enhance computability2 if it can be scaled to a large number of Quantum bits (qubits). It was realized early on that a hybrid system of light qubits and matter qubits3 could solve the scalability problem of each field—that of communication by use of Quantum repeaters4, and that of computation by use of an optical interconnect between smaller Quantum processors5,6. To this end, the development of a robust two-qubit Gate that allows the linking of distant computational nodes is “a pressing challenge”6. Here we demonstrate such a Quantum Gate between the spin state of a single trapped atom and the polarization state of an optical photon contained in a faint laser pulse. The Gate mechanism presented7,8 is deterministic and robust, and is expected to be applicable to almost any matter qubit. It is based on reflection of the photonic qubit from a cavity that provides strong light–matter coupling. To demonstrate its versatility, we use the Quantum Gate to create atom–photon, atom–photon–photon and photon–photon entangled states from separable input states. We expect our experiment to enable various applications, including the generation of atomic9 and photonic10 cluster states and Schrodinger-cat states11, deterministic photonic Bell-state measurements12, scalable Quantum computation7 and Quantum communication using a redundant Quantum parity code13.
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a Quantum Gate between a flying optical photon and a single trapped atom
Nature, 2014Co-Authors: Andreas Reiserer, N Kalb, Gerhard Rempe, Stephan RitterAbstract:After demonstration of the conditional phase shift mechanism in Reiserer et al. (Science 342(6164):1349–1351, 2013), it was also applied to demonstrate an atom-photon Quantum Gate, which is described in the following.
Stephan Durr - One of the best experts on this subject based on the ideXlab platform.
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a photon photon Quantum Gate based on rydberg interactions
Nature Physics, 2019Co-Authors: Daniel Tiarks, Gerhard Rempe, Steffen Schmidteberle, Thomas Stolz, Stephan DurrAbstract:The interaction between Rydberg states of neutral atoms is strong and long-range, making it appealing to put it to use in the context of Quantum technologies. Recently, first applications of this idea have been reported in the fields of Quantum computation1 and Quantum simulation2–4. Furthermore, electromagnetically induced transparency allows one to map these Rydberg interactions to light5–15. Here we exploit this mapping and the resulting interaction between photons to realize a photon–photon Quantum Gate16,17, demonstrating the potential of Rydberg systems as a platform also for Quantum communication and Quantum networking18. We measure a controlled-NOT truth table with a fidelity of 70(8)% and an entangling-Gate fidelity of 63.7(4.5)%, both post-selected upon detection of a control and a target photon. The level of control reached here is an encouraging step towards exploring novel many-body states of photons or for future applications in Quantum communication and Quantum networking18. Strong and long-range interactions between Rydberg states of neutral atoms can be mapped to light via electromagnetically induced transparency, realizing a photon–photon Quantum Gate for Quantum communications and networking.
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a photon photon Quantum Gate based on rydberg interactions
arXiv: Quantum Physics, 2018Co-Authors: Daniel Tiarks, Gerhard Rempe, Steffen Schmidteberle, Thomas Stolz, Stephan DurrAbstract:The interaction between Rydberg states of neutral atoms is strong and long-range, making it appealing to put it to use in the context of Quantum technologies. Recently, first applications of this idea have been reported in the fields of Quantum computation and Quantum simulation. Furthermore, electromagnetically induced transparency allows to map these Rydberg interactions to light. Here we exploit this mapping and the resulting interaction between photons to realize a photon-photon Quantum Gate, demonstrating the potential of Rydberg systems as a platform also for Quantum communication and Quantum networking. We measure a controlled-NOT truth table with a fidelity of 70(8)% and an entangling-Gate fidelity of 63.7(4.5)%, both post-selected upon detection of a control and a target photon. The level of control reached here is an encouraging step towards exploring novel many-body states of photons or for future applications in Quantum communication and Quantum networking.
Bastian Hacker - One of the best experts on this subject based on the ideXlab platform.
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photon mediated Quantum Gate between two neutral atoms in an optical cavity
Physical Review X, 2018Co-Authors: Stephan Welte, Stephan Ritter, Bastian Hacker, Severin Daiss, Gerhard RempeAbstract:Quantum communication requires the ability for network nodes to send and receive photons as well as process Quantum information. New experiments demonstrate just such a Quantum Gate, realized by two neutral atoms coupled by an optical photon.
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a photon photon Quantum Gate based on a single atom in an optical resonator
Nature, 2016Co-Authors: Bastian Hacker, Gerhard Rempe, Stephan Welte, Stephan RitterAbstract:To enable two photons to interact, a single atom in an optical resonator is used to build a universal photon–photon Quantum Gate; this could lead to applications in long-distance Quantum communication and scalable Quantum computing that require the processing of optical Quantum information. Two beams of light sharing the same space tend not to interact with one another. Yet if purely photonic technologies such as Quantum communication and scalable Quantum computing are to be developed — which require components such as switches and logic Gates — it will be important to find conditions that facilitate controllable interactions between two photons. To that end, various single-photon Quantum devices have been demonstrated in recent years, typically involving interactions between photons and atoms in a resonator. Here Stephan Ritter and colleagues employ such a system to make a logic component for Quantum operations — a universal controlled phase flip photon–photon Quantum Gate — that involves interaction between two individual input photons mediated by a single atom. That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical Quantum information processing1. The long-standing challenge here is to realize a deterministic photon–photon Gate, that is, a mutually controlled logic operation on the Quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other’s phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon’s polarization to an orthogonal state. So far, only probabilistic Gates2 based on linear optics and photon detectors have been realized3, because “no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift”4. Meanwhile, tremendous progress in the development of Quantum-nonlinear systems has opened up new possibilities for single-photon experiments5. Platforms range from Rydberg blockade in atomic ensembles6 to single-atom cavity Quantum electrodynamics7. Applications such as single-photon switches8 and transistors9,10, two-photon Gateways11, nondestructive photon detectors12, photon routers13 and nonlinear phase shifters14,15,16,17,18 have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light–matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan–Kimble protocol19 of a universal controlled phase flip (π phase shift) photon–photon Quantum Gate. We achieve an average Gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon–photon Quantum Gate is a universal Quantum logic element, and therefore could perform most existing two-photon operations. The demonstrated feasibility of deterministic protocols for the optical processing of Quantum information could lead to new applications in which photons are essential, especially long-distance Quantum communication and scalable Quantum computing.
