English
Related papers

Related papers: Dephasing and Measurement Efficiency via a Quantum…

200 papers

We present an effective measurement scheme for the solid-state qubits that does {\bf not} introduce extra decoherence to the qubits until the measurement is switched on by a resonant pulse. The resonant pulse then maximally entangles the…

Quantum Physics · Physics 2011-07-26 L. Tian , S. Lloyd , T. P. Orlando

We report on charge sensing measurements of a GaAs semiconductor quantum dot device using a radio frequency quantum point contact (rf-QPC). The rf-QPC is fully characterized at 4 K and milli-Kelvin temperatures and found to have a bandwidth…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 M. C. Cassidy , A. S. Dzurak , R. G. Clark , K. D. Petersson , I. Farrer , D. A. Ritchie , C. G. Smith

The concept of quantum nondemolition (QND) measurement is extended to coherent oscillations in an individual two-state system. Such a measurement enables direct observation of intrinsic spectrum of these oscillations avoiding the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 D. V. Averin

Quantum transport in mesoscopic conductors is essentially governed by the laws of quantum mechanics. One of the major open questions of quantum mechanics is what happens if non-commuting observables are measured simultaneously. Since…

Mesoscale and Nanoscale Physics · Physics 2010-03-15 Adam Bednorz , Wolfgang Belzig

The characterization and mitigation of decoherence in natural and artificial two-level systems (qubits) is fundamental to quantum information science and its applications. Decoherence of a quantum superposition state arises from the…

A pulsed balanced homodyne detector has been developed for precise measurements of electric field quadratures of pulsed optical quantum states. A high level of common mode suppression (> 85 dB) and low electronic noise (730 electrons per…

Quantum Physics · Physics 2009-11-07 H. Hansen , T. Aichele , C. Hettich , P. Lodahl , A. I. Lvovsky , J. Mlynek , S. Schiller

Quantum battery (QB) is the miniature energy storage and release device and plays a crucial role in future quantum technology. Here, an implementation scheme of a QB is proposed on a superconducting circuit which is composed by $N$ coupled…

Quantum Physics · Physics 2023-03-15 Fu-Quan Dou , Fang-Mei Yang

We study the performance of a single qubit-laser as a quantum sensor to measure the amplitude and phase of a driving field. By using parameter estimation theory we show that certain suitable field quadratures are optimal observables in the…

Quantum Physics · Physics 2017-07-19 Samuel Fernández-Lorenzo , Diego Porras

Kondo correlation in a spin polarized quantum dot (QD) results from the dynamical formation of a spin singlet between the dot's net spin and a Kondo cloud of electrons in the leads, leading to enhanced coherent transport through the QD. We…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Avinun-Kalish , M. Heiblum , A. Silva , D. Mahalu , V. Umansky

We demonstrate full suppression of dephasing tied to deformation potential coupling of confined electrons to longitunidal acoustic (LA) phonons in optical control experiments on large semiconductor quantum dots (QDs) with emission…

Mesoscale and Nanoscale Physics · Physics 2020-12-07 A. Ramachandran , G. R. Wilbur , S. O'Neal , D. G. Deppe , K. C. Hall

Quantum phase fluctuations play a crucial role in low dimensional systems. In particular they prevent true long range phase order from forming in one dimensional condensates, even at zero temperature. Nevertheless, by dynamically splitting…

Other Condensed Matter · Physics 2009-11-11 Rafi Bistritzer , Ehud Altman

Quantum dots are frequently used as charge sensitive devices in low temperature experiments to probe electric charge in mesoscopic conductors where the current running through the quantum dot is modulated by the nearby charge environment.…

Mesoscale and Nanoscale Physics · Physics 2024-01-12 Harald Havir , Subhomoy Haldar , Waqar Khan , Sebastian Lehmann , Kimberly A. Dick , Claes Thelander , Peter Samuelsson , Ville F. Maisi

We analyze dephasing in a model system where electrons tunnel sequentially through a symmetric interference setup consisting of two single-level quantum dots. Depending on the phase difference between the two tunneling paths, this may…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Florian Marquardt , C. Bruder

A sensitive technique for the readout of the state of a qubit is based on the measurement of the conductance through a proximal sensor quantum dot (SQD). Here, we theoretically study the coherent backaction of such a measurement on a…

Mesoscale and Nanoscale Physics · Physics 2016-04-19 M. Hell , M. R. Wegewijs , D. P. DiVincenzo

Distributed detection primarily centers around two approaches: Unquantized Distributed Detection (UDD), where each sensor reports its complete observation to the fusion center (FC), and quantized-and-Coded DD (CDD), where each sensor first…

Information Theory · Computer Science 2023-11-07 Lei Cao , Ramanarayanan Viswanathan

Detection of signals buried in noise is the major challenge for sensing. Classically, the optimal detector is a matched filter, whose sensitivity meets the classical limit of correlation between the filter target and the measured signal…

A well-balanced detector with high sensitivity and low noise is presented in this paper. The two-stage amplification structure is used to increase electronic gain while keeping an effective bandwidth of about 70 MHz. In order to further…

Instrumentation and Detectors · Physics 2018-06-13 Qi-Ming Lu , Qi Shen , Yuan Cao , Sheng-Kai Liao , Cheng-Zhi Peng

Thorough control of quantum measurement is key to the development of quantum information technologies. Many measurements are destructive, removing more information from the system than they obtain. Quantum non-demolition (QND) measurements…

Measurement-device-independent quantum key distribution (MDI-QKD), which eliminates all the attacks from the eavesdropper to the measurement party, has been one of the most promising technology for the implementation of end-to-end quantum…

The quantum cryptographic conferencing (QCC) protocol, which distributes identical secure keys to user groups, is a crucial component of the quantum network. Previous experimental works have implemented the measurement-device-independent…

Quantum Physics · Physics 2026-02-25 Yifeng Du , Yang Hu , Yufeng Liu , Wenhan Yan , Jinghao Zhang , Shining Zhu , Xiao-Song Ma