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Detecting and characterizing decoherence-inducing noise sources is critical for developing robust quantum technologies and deploying quantum sensors operating at molecular scales. However, current noise spectroscopies rely on severe…

Quantum Physics · Physics 2025-07-09 Nanako Shitara , Andrés Montoya-Castillo

Quantum systems can be used to measure various quantities in their environment with high precision. Often, however, their sensitivity is limited by the decohering effects of this same environment. Dynamical decoupling schemes are widely…

Quantum Physics · Physics 2018-07-18 David Layden , Paola Cappellaro

Exploring the noise spectrum impacting a qubit and extending its coherence duration are fundamental components of quantum technologies. In this study, we introduce parametric spectroscopy, a method that merges parametric modulation of a…

Quantum Physics · Physics 2025-03-10 Nir Gavrielov , Santiago Oviedo-Casado , Alex Retzker

An optimal dynamical decoupling of a quantum system coupled to a noisy environment must take into account also the imperfections of the control pulses. We present a new formalism which describes, in a closed-form expression, the evolution…

Quantum Physics · Physics 2016-10-19 Ido Almog , Gil Loewenthal , Jonathan Coslovsky , Yoav Sagi , Nir Davidson

The interaction of a quantum system, which is not accessible by direct measurement, with an external probe can be exploited to infer specific features of the system itself. We introduce a probing scheme based on the emergence of spontaneous…

Quantum Physics · Physics 2016-11-21 Gian Luca Giorgi , Fernando Galve , Roberta Zambrini

We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's…

Resilience to noise and to decoherence processes is an important ingredient for the implementation of quantum information processing, and quantum technologies. To this end, techniques such as pulsed and continuous dynamical decoupling have…

Quantum Physics · Physics 2016-12-02 Itsik Cohen , Nati Aharon , Alex Retzker

We study the dissipative dynamics of a qubit that is afflicted by classical random telegraph noise and it is subject to dynamical decoupling. We derive exact formulas for the qubit dynamics at arbitrary working points in the limit of…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Joakim Bergli , Lara Faoro

We consider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer…

Quantum Physics · Physics 2016-08-03 Gerardo A. Paz-Silva , Seung-Woo Lee , Todd J. Green , Lorenza Viola

We present a procedure for direct characterization of the dephasing noise acting on a single qubit by making repeated measurements of the qubit coherence under suitably chosen sequences of controls. We show that this allows a numerical…

Quantum Physics · Physics 2013-05-30 Kevin C. Young , K. Birgitta Whaley

We introduce open-loop quantum control protocols for characterizing the spectral properties of non-Gaussian noise, applicable to both classical and quantum dephasing environments. The basic idea is to engineer a multi-dimensional frequency…

Quantum Physics · Physics 2016-04-20 Leigh M. Norris , Gerardo A. Paz-Silva , Lorenza Viola

We consider the usage of dynamical decoupling in quantum metrology, where the joint evolution of system plus environment is described by a Hamiltonian. We demonstrate that by ultra-fast unitary control operations acting locally only on…

Quantum Physics · Physics 2016-08-03 P. Sekatski , M. Skotiniotis , W. Dür

Quantum metrology with entangled states in realistic noisy environments always suffers from decoherence. Therefore, the measurement precision is greatly reduced. Here we applied the dynamical decoupling method to protect the $N$-qubit…

Quantum Physics · Physics 2016-12-21 Yang Dong , Xiang-Dong Chen , Guang-Can Guo , Fang-Wen Sun

Dynamical decoupling is a technique that protects qubits against noise. The ability to preserve quantum coherence in the presence of noise is essential for the development of quantum devices. Here the Rigetti quantum computing platform was…

Quantum Physics · Physics 2022-02-08 Alexandre M. Souza

A method is proposed for obtaining the spectrum for noise that causes the phase decoherence of a qubit directly from experimentally available data. The method is based on a simple relationship between the spectrum and the coherence time of…

Quantum Physics · Physics 2015-05-28 Tatsuro Yuge , Susumu Sasaki , Yoshiro Hirayama

The noise of a device under test (DUT) is measured simultaneously with two instruments, each of which contributes its own background. The average cross power spectral density converges to the DUT power spectral density. This method enables…

Instrumentation and Detectors · Physics 2010-03-02 Enrico Rubiola , Francois Vernotte

The interaction between solid-state qubits and their environmental degrees of freedom produces non-unitary effects like decoherence and dissipation. Uncontrolled decoherence is one of the main obstacles that must be overcome in quantum…

Quantum Physics · Physics 2014-11-24 Paula I. Villar , Fernando C. Lombardo

We introduce a novel method that we call Single-Shot Cross-Spectroscopy (SSCS), for extracting the auto- and cross-power spectral densities of dephasing noise of a qubit pair. The method uses straightforward input, namely single-shot…

Quantum Physics · Physics 2025-09-29 Juan S. Rojas-Arias , Peter Stano , Yi-Hsien Wu , Leon C. Camenzind , Seigo Tarucha , Daniel Loss

Knowing a quantum system's environment is critical for its practical use as a quantum device. Qubit sensors can reconstruct the noise spectral density of a classical bath, provided long enough coherence time. Here we present a protocol that…

Quantum Physics · Physics 2018-12-20 Santiago Hernández-Gómez , Francesco Poggiali , Paola Cappellaro , Nicole Fabbri

One approach to maintaining phase coherence of qubits through dynamical decoupling consists of applying a sequence of Hahn spin-echo pulses. Recent studies have shown that, in certain noise environments, judicious choice of the delay times…

Quantum Physics · Physics 2009-06-24 Hermann Uys , Michael J. Biercuk , John J. Bollinger