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Dynamical decoupling pulse sequences have been used to extend coherence times in quantum systems ever since the discovery of the spin-echo effect. Here we introduce a method of recursively concatenated dynamical decoupling pulses, designed…

Quantum Physics · Physics 2007-05-23 K. Khodjasteh , D. A. Lidar

We perform Ramsey interferometry on an ultracold 87Rb ensemble confined in an optical dipoletrap. We use a \pi-pulse set at the middle of the interferometer to restore the coherence of the spinensemble by canceling out phase inhomogeneities…

The spin echo approach is extended to include bio-complexes for which the interaction with dynamical noise is strong. Significant restoration of the free induction decay signal due to homogeneous (decoherence) and inhomogeneous (dephasing)…

Biological Physics · Physics 2015-05-13 Alexander I. Nesterov , Gennady P. Berman

We have characterized a novel photon-echo pulse sequence for a double-$\Lambda$ type energy level system where the input and rephasing transitions are different to the applied $\pi$-pulses. We show that despite having imperfect $\pi$-pulses…

Quantum Physics · Physics 2015-05-20 Sarah E. Beavan , Patrick M. Ledingham , Jevon J. Longdell , Matthew J. Sellars

We report a measurement of the spin-echo decay of a single electron spin confined in a semiconductor quantum dot. When we tip the spin in the transverse plane via a magnetic field burst, it dephases in 37 ns due to the Larmor precession…

Mesoscale and Nanoscale Physics · Physics 2009-08-17 F. H. L. Koppens , K. C. Nowack , L. M. K. Vandersypen

Spin-based quantum computing and magnetic resonance techniques rely on the ability to measure the coherence time, T2, of a spin system. We report on the experimental implementation of all-optical spin echo to determine the T2 time of a…

Spin-echo instruments are typically used to measure diffusive processes and the dynamics and motion in samples on ps and ns timescales. A key aspect of the spin-echo technique is to determine the polarisation of a particle beam. We present…

Materials Science · Physics 2018-02-05 Anton Tamtögl , Benjamin Davey , David J. Ward , Andrew P. Jardine , John Ellis , William Allison

In Echo experiments, imperfect time-reversal operations are performed on a subset of the total number of degrees of freedom. To capture the physics of these experiments, we introduce a partial fidelity, the Boltzmann echo, where only part…

Quantum Physics · Physics 2009-11-13 Cyril Petitjean , Philippe Jacquod

Semiconductor quantum dots are excellent candidates for ultrafast coherent manipulation of qubits by laser pulses on picosecond timescales or even faster. In inhomogeneous ensembles a macroscopic optical polarization decays rapidly due to…

Mesoscale and Nanoscale Physics · Physics 2020-06-11 A. N. Kosarev , H. Rose , S. V. Poltavtsev , M. Reichelt , C. Schneider , M. Kamp , S. Hoefling , M. Bayer , T. Meier , I. A. Akimov

The electrical detection of spin echoes via echo tomography is used to observe decoherence processes associated with the electrical readout of the spin state of phosphorus donor electrons in silicon near a SiO$_2$ interface. Using the…

Quantum Physics · Physics 2008-05-06 Hans Huebl , Felix Hoehne , Benno Grolik , Andre R. Stegner , Martin Stutzmann , Martin S. Brandt

Pulses applied to an inhomogeneously broadened set of harmonic oscillators, previously prepared in squeezed states, can lead to a recovery of coherence, manifesting itself as echoes, similar to those exhibited by an ensemble of spins when…

Quantum Physics · Physics 2021-01-13 Roberto Merlin , Andrea Bianchini

Fast quantum oscillations of a charge qubit in a double quantum dot fabricated in a Si/SiGe heterostructure are demonstrated and characterized experimentally. The measured inhomogeneous dephasing time T2* ranges from 127ps to ~2.1ns; it…

In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 Junkai Zeng , Xiu-Hao Deng , Antonio Russo , Edwin Barnes

We employ the Loschmidt Echo, i.e. the signal recovered after the reversal of an evolution, to identify and quantify the processes contributing to decoherence. This procedure, which has been extensively used in single particle physics, is…

Quantum Physics · Physics 2012-07-25 Pablo R. Zangara , Axel D. Dente , Patricia R. Levstein , Horacio M. Pastawski

Echo is a ubiquitous phenomenon found in many physical systems, ranging from spins in magnetic fields to particle beams in hadron accelerators. It is typically observed in inhomogeneously broadened ensembles of nonlinear objects, and is…

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…

The application of dynamical decoupling pulses to a single qubit interacting with a linear harmonic oscillator bath with $1/f$ spectral density is studied, and compared to the Ohmic case. Decoupling pulses that are slower than the fastest…

Quantum Physics · Physics 2009-11-07 K. Shiokawa , D. A. Lidar

Spectral characterization of noise environments that lead to the decoherence of qubits is critical to developing robust quantum technologies. While dynamical decoupling offers one of the most successful approaches to characterize noise…

Quantum Physics · Physics 2024-05-21 Arian Vezvaee , Nanako Shitara , Shuo Sun , Andrés Montoya-Castillo

We show that one of the key characteristics of interacting one-dimensional electronic quantum systems, the separation of spin and charge, can be observed in a two-component system of bosonic ultracold atoms even close to a competing phase…

Other Condensed Matter · Physics 2008-03-01 A. Kleine , C. Kollath , I. McCulloch , T. Giamarchi , U. Schollwoeck

In Si/SiGe quantum dots, the decoherence behavior of spin qubits usually comes from the non-Markovian effect of the charge noise. To improve the performance of using the coherent noise models in the decoherence simulation and tomography…

Quantum Physics · Physics 2025-10-28 Wei-en Chiu , Chia-Hsien Huang , Yi-Hsien Wu , Hsi-Sheng Goan
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