Wolfgang Pfaff
Yale University
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Publication
Featured researches published by Wolfgang Pfaff.
Applied Physics Letters | 2011
T. van der Sar; Jenna Hagemeier; Wolfgang Pfaff; E. C. Heeres; Susanna M. Thon; Hyochul Kim; P. M. Petroff; Tjerk H. Oosterkamp; Dirk Bouwmeester; R. Hanson
Controlling the interaction of a single quantum emitter with its environment is a key challenge in quantum optics. Here, we demonstrate deterministic coupling of single nitrogen-vacancy (NV) centers to high-quality photonic crystal cavities. We preselect single NV centers and position their 50-nm-sized host nanocrystals into the mode maximum of photonic crystal S1 cavities with few-nanometer accuracy. The coupling results in a strong enhancement of NV center emission at the cavity wavelength.
Nature Physics | 2013
Wolfgang Pfaff; T. H. Taminiau; Lucio Robledo; Hannes Bernien; Matthew Markham; Daniel Twitchen; R. Hanson
Entanglement is an important resource in quantum-enhanced technologies, but it is difficult to generate, especially in solid-state systems. An experiment now demonstrates the entanglement of two nuclear spins via a parity measurement of the electron spin in a nitrogen-vacancy centre in diamond.
Physical Review B | 2016
Matthew Reagor; Wolfgang Pfaff; Christopher Axline; Reinier Heeres; Nissim Ofek; Katrina Sliwa; Eric Holland; Chen Wang; Jacob Blumoff; Kevin Chou; M. Hatridge; Luigi Frunzio; Michel H. Devoret; Liang Jiang; R. J. Schoelkopf
Significant advances in coherence render superconducting quantum circuits a viable platform for fault-tolerant quantum computing. To further extend capabilities, highly coherent quantum systems could act as quantum memories for these circuits. A useful quantum memory must be rapidly addressable by Josephson-junction-based artificial atoms, while maintaining superior coherence. We demonstrate a superconducting microwave cavity architecture that is highly robust against major sources of loss that are encountered in the engineering of circuit QED systems. The architecture allows for storage of quantum superpositions in a resonator on the millisecond scale, while strong coupling between the resonator and a transmon qubit enables control, encoding, and readout at MHz rates. This extends the maximum available coherence time attainable in superconducting circuits by almost an order of magnitude compared to earlier hardware. Our design is an ideal platform for studying coherent quantum optics and marks an important step towards hardware-efficient quantum computing in Josephson-junction-based quantum circuits.
Physical Review X | 2016
A. Narla; S. Shankar; M. Hatridge; Zaki Leghtas; Katrina Sliwa; E. Zalys-Geller; S.O. Mundhada; Wolfgang Pfaff; Luigi Frunzio; R. J. Schoelkopf; Michel H. Devoret
Entangling two remote quantum systems which never interact directly is an essential primitive in quantum information science and forms the basis for the modular architecture of quantum computing. When protocols to generate these remote entangled pairs rely on using traveling single photon states as carriers of quantum information, they can be made robust to photon losses, unlike schemes that rely on continuous variable states. However, efficiently detecting single photons is challenging in the domain of superconducting quantum circuits because of the low energy of microwave quanta. Here, we report the realization of a robust form of concurrent remote entanglement based on a novel microwave photon detector implemented in the superconducting circuit quantum electrodynamics (cQED) platform of quantum information. Remote entangled pairs with a fidelity of
Applied Physics Letters | 2015
T. Brecht; Matthew Reagor; Yiwen Chu; Wolfgang Pfaff; C. Wang; Luigi Frunzio; Michel H. Devoret; R. J. Schoelkopf
0.57\pm0.01
Applied Physics Letters | 2016
Christopher Axline; Matthew Reagor; Reinier Heeres; Philip Reinhold; Chen Wang; Kevin Shain; Wolfgang Pfaff; Yiwen Chu; Luigi Frunzio; R. J. Schoelkopf
are generated at
Journal of Applied Physics | 2013
Wolfgang Pfaff; Arthur Vos; R. Hanson
200
Nature Physics | 2017
Wolfgang Pfaff; Christopher Axline; Luke Burkhart; U. Vool; Philip Reinhold; Luigi Frunzio; Liang Jiang; Michel H. Devoret; R. J. Schoelkopf
Hz. Our experiment opens the way for the implementation of the modular architecture of quantum computation with superconducting qubits.
Nature Physics | 2017
A. P. Reed; K. H. Mayer; J. D. Teufel; Luke Burkhart; Wolfgang Pfaff; Matthew Reagor; Lucas R. Sletten; X. Ma; R. J. Schoelkopf; Emanuel Knill; K. W. Lehnert
Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.
Nature Physics | 2018
Christopher Axline; Luke Burkhart; Wolfgang Pfaff; Mengzhen Zhang; Kevin Chou; Philippe Campagne-Ibarcq; Philip Reinhold; Luigi Frunzio; S. M. Girvin; Liang Jiang; Michel H. Devoret; R. J. Schoelkopf
Numerous loss mechanisms can limit coherence and scalability of planar and 3D-based circuit quantum electrodynamics (cQED) devices, particularly due to their packaging. The low loss and natural isolation of 3D enclosures make them good candidates for coherent scaling. We introduce a coaxial transmission line device architecture with coherence similar to traditional 3D cQED systems. Measurements demonstrate wellcontrolled external and on-chip couplings, a spectrum absent of cross-talk or spurious modes, and excellent resonator and qubit lifetimes. We integrate a resonator-qubit system in this architecture with a seamless 3D cavity, and separately pattern a qubit, readout resonator, Purcell filter and high-Q stripline resonator on a single chip. Device coherence and its ease of integration make this a promising tool for complex experiments.Numerous loss mechanisms can limit coherence and scalability of planar and 3D-based circuit quantum electrodynamics (cQED) devices, particularly due to their packaging. The low loss and natural isolation of 3D enclosures make them good candidates for coherent scaling. We introduce a coaxial transmission line device architecture with coherence similar to traditional 3D cQED systems. Measurements demonstrate well-controlled external and on-chip couplings, a spectrum absent of cross-talk or spurious modes, and excellent resonator and qubit lifetimes. We integrate a resonator-qubit system in this architecture with a seamless 3D cavity, and separately pattern a qubit, readout resonator, Purcell filter, and high-Q stripline resonator on a single chip. Device coherence and its ease of integration make this a promising tool for complex experiments.