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Related papers: Dephasing and Measurement Efficiency via a Quantum…

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We present a method for measuring the internal state of a superconducting qubit inside an on-chip microwave resonator. We show that one qubit state can be associated with the generation of an increasingly large cavity coherent field, while…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 B. G. U. Englert , G. Mangano , M. Mariantoni , R. Gross , J. Siewert , E. Solano

We employ detuning-dependent decay-rate measurements of a quantum dot in a photonic-crystal cavity to study the influence of phonon dephasing in a solid-state quantum-electrodynamics experiment. The experimental data agree with a…

Mesoscale and Nanoscale Physics · Physics 2013-08-08 K. H. Madsen , P. Kaer , A. Kreiner-Møller , S. Stobbe , A. Nysteen , J. Mørk , P. Lodahl

The extension of quantum trajectory theory to incorporate realistic imperfections in the measurement of solid-state qubits is important for quantum computation, particularly for the purposes of state preparation and error-correction as well…

Mesoscale and Nanoscale Physics · Physics 2008-03-06 Neil P. Oxtoby , Jay Gambetta , H. M. Wiseman

The Multiple Amplifier Sensing Charge-Coupled Device (MAS-CCD) has emerged as a promising technology for astronomical observation, quantum imaging, and low-energy particle detection due to its ability to reduce the readout noise without…

We study the dynamics of quantum coherence and quantum correlations in two semiconductor double-dot molecules separated by a distance and indirectly coupled via a transmission line resonator. Dominant dissipation processes are considered.…

Quantum Physics · Physics 2012-05-08 Pei Pei , Chong Li , Jia-Sen Jin , He-Shan Song

We compare critical quantum sensing to passive quantum strategies to perform frequency estimation, in the case of single-mode quadratic Hamiltonians. We show that, while in the unitary case both strategies achieve precision scaling…

Quantum Physics · Physics 2024-08-07 Uesli Alushi , Wojciech Górecki , Simone Felicetti , Roberto Di Candia

The quantum rectification effect observed on asymmetric superconducting loops is proposed to use as a basic of a noise detector with maximum sensitivity. The measurements show that a critical amplitude of noise or ac current decreases down…

Superconductivity · Physics 2007-05-23 V. L. Gurtovoi , S. V. Dubonos , R. V. Kholin , A. V. Nikulov , N. N. Osipov , V. A. Tulin

In many leading architectures for quantum computing, it remains to be understood if we can equate single-qubit coherence times measured in isolation, to that of coherence times measured in multi-qubit devices. On a multi-qubit…

Quantum Physics · Physics 2024-08-06 Petar Jurcevic , Luke C. G. Govia

Quantum metrology utilizes entanglement for improving the sensitivity of measurements. Up to now the focus has been on the measurement of just one out of two non-commuting observables. Here we demonstrate a laser interferometer that…

Off-resonant interaction of fluctuating photons in a resonator with a qubit increases the qubit dephasing rate. We use this effect to measure a small average number of intracavity photons that are coherently or thermally driven. For…

Quantum Physics · Physics 2023-10-26 Juan Atalaya , Alex Opremcak , Ani Nersisyan , Kenny Lee , Alexander N. Korotkov

We present measurements of the fourth and fifth cumulants of the distribution of transmitted charge in a tunable quantum dot. We investigate how the measured statistics is influenced by the finite bandwidth of the detector and by the finite…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 S. Gustavsson , R. Leturcq , T. Ihn , K. Ensslin , M. Reinwald , W. Wegscheider

Photon detectors are an elementary tool to measure electromagnetic waves at the quantum limit and are heavily demanded in the emerging quantum technologies such as communication, sensing, and computing. Of particular interest is a quantum…

Quantum Physics · Physics 2018-07-04 S. Kono , K. Koshino , Y. Tabuchi , A. Noguchi , Y. Nakamura

We demonstrate improved operation of exchange-coupled semiconductor quantum dots by substantially reducing the sensitivity of exchange operations to charge noise. The method involves biasing a double-dot symmetrically between the…

We demonstrate a sub-shot-noise-limit discrimination of on-off keyed coherent signals by an optimal displacement quantum receiver in which a superconducting transition edge sensor is installed. Use of a transition edge sensor and a fiber…

We demonstrate charge sensing of an InAs nanowire double quantum dot (DQD) coupled to a radio frequency (rf) circuit. We measure the rf signal reflected by the resonator using homodyne detection. Clear single dot and DQD behavior are…

Mesoscale and Nanoscale Physics · Physics 2013-07-24 M. Jung , M. D. Schroer , K. D. Petersson , J. R. Petta

In this work we propose a microwave photon detector which successfully reaches 100% efficiency with only one absorber. Our design consists of a metastable quantum circuit coupled to a semi-infinite transmission line which performs highly…

Mesoscale and Nanoscale Physics · Physics 2012-03-22 B. Peropadre , G. Romero , G. Johansson , C. M. Wilson , E. Solano , J. J. García-Ripoll

The generation of indistinguishable single photons is a fundamental requirement for future quantum technologies, particularly in quantum repeater networks and for distributed quantum computing based on entanglement distribution. However,…

Interpretation of experiments on quantum dot (QD) lasers presents a challenge: the phonon bottleneck, which should strongly suppress relaxation and dephasing of the discrete energy states, often seems to be inoperative. We suggest and…

Condensed Matter · Physics 2009-10-31 A. V. Uskov , A. -P. Jauho , B. Tromborg , J. Mork , R. Lang

Within a circuit quantum electrodynamics architecture, we theoretically investigate the detection of a single propagating microwave photon traveling through a resonant microwave cavity dispersively interacting with a double quantum dot…

Mesoscale and Nanoscale Physics · Physics 2025-11-25 Stephanie Matern , Alberto Biella , Pasquale Scarlino , Iacopo Carusotto , Gianluca Rastelli

Coupling a microscopic mechanical resonator to a nano-scale quantum system enables control of the mechanical resonator via the quantum system, and vice versa. The coupling is usually achieved through functionalization of the mechanical…