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Related papers: Upper bound on the duration of quantum jumps

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The quantum interaction between free electrons and photons is fundamental to free-electron based light sources and free-electron quantum optics applications. A large coupling between free electrons and photons is generally desired. In this…

Quantum Physics · Physics 2024-11-08 Zhexin Zhao

The traditional quantum speed limits are not attainable for many physical processes, as they tend to be loose and fail to determine the exact time taken by quantum systems to evolve. To address this, we derive exact quantum speed limits for…

Quantum Physics · Physics 2023-08-30 Arun K. Pati , Brij Mohan , Sahil , Samuel L. Braunstein

We first use the quantum method to replicate the well-known results of a single atom relaxing, whilst demonstrating the intuitive picture it provides for dissipative dynamics. By use of individual "quantum trajectories", the method allows…

Quantum Physics · Physics 2022-02-10 Charles A. McDermott

A consistent theory describing the dynamics of quantum systems interacting on a classical space-time was recently put forward by Oppenheim et al..[1, 2]. Quantum states may retain their coherence, at the cost of some amount of stochasticity…

In this paper, we derive sharp lower bounds, also known as quantum speed limits, for the time it takes to transform a quantum system into a state such that an observable assumes its lowest average value. We assume that the system is…

Quantum Physics · Physics 2021-06-02 Dan Allan , Niklas Hörnedal , Ole Andersson

A quantum system subjected to a strong continuous monitoring undergoes quantum jumps. This very well known fact hides a neglected subtlety: sharp scale-invariant fluctuations invariably decorate the jump process even in the limit where the…

Quantum Physics · Physics 2015-11-19 Antoine Tilloy , Michel Bauer , Denis Bernard

Tunnelling is one of the most paradigmatic and evocative phenomena of quantum physics, underlying processes such as photosynthesis and nuclear fusion, as well as devices ranging from SQUID magnetometers to superconducting qubits for quantum…

Atomic Physics · Physics 2019-08-02 Ramón Ramos , David Spierings , Isabelle Racicot , Aephraim M. Steinberg

We characterize a source of photon pairs based on cascade decay in a cold Rb-87 ensemble. This source is particularly suited to generate of photons for interaction with Rb-87 based atomic systems. We experimentally investigate the…

A theory of quantum jumps is developed by using a new asymmetric equation, which is complementary to the Schr\"odinger equation. The new equation displays Bohr's rules for quantum jumps, and its solutions demonstrate that once a quantum…

General Physics · Physics 2025-09-23 Z. E. Musielak

We model a particle entering a complicated system from free space using an infinite chain of simple harmonic oscillators coupled to a finite, $n$-site cluster. For a particle wavepacket with small wavenumber, an expression for the time…

Quantum Physics · Physics 2018-12-13 Erin Crawley

Quantum metrology enhances measurement precision by utilising the properties of quantum physics. In interferometry, this is typically achieved by evolving highly-entangled quantum states before performing single-shot measurements to reveal…

Quantum Physics · Physics 2023-01-11 Kawthar Al Rasbi , Almut Beige , Lewis A. Clark

Quantum speed limits provide upper bounds on the rate with which a quantum system can move away from its initial state. Here, we provide a different kind of speed limit, describing the divergence of a perturbed open system from its…

Quantum Physics · Physics 2024-08-28 Benjamin Yadin , Satoya Imai , Otfried Gühne

We consider the general scenario of an excited level |i> of a quantum system that can decay via two channels: (i) via a single-quantum jump to an intermediate, resonant level |bar m>, followed by a second single-quantum jump to a final…

Atomic Physics · Physics 2010-01-25 U. D. Jentschura

We describe the absorption by the walls of a quantum electrodynamics cavity as a process during which the elementary excitations (photons) of an internal mode of the cavity exit by tunneling through the cavity walls. We estimate by…

Quantum Physics · Physics 2015-06-12 V. Debierre , G. Demésy , T. Durt , A. Nicolet , B. Vial , F. Zolla

We propose an entanglement generation scheme that requires neither the coherent evolution of a quantum system nor the detection of single photons. Instead, the desired state is heralded by a {\em macroscopic} quantum jump. Macroscopic…

Quantum Physics · Physics 2009-11-11 Jeremy Metz , Michael Trupke , Almut Beige

Measuring the thermodynamic properties of open quantum systems poses a major challenge. A calorimetric detection has been proposed as a feasible experimental scheme to measure work and fluctuation relations in open quantum systems. However,…

Quantum Physics · Physics 2016-06-15 Samu Suomela , Aki Kutvonen , Tapio Ala-Nissila

We demonstrate the ultimate sensitivity allowed by quantum physics in the estimation of the time delay between two photons by measuring their interference at a beam-splitter through frequency-resolving sampling measurements. This…

Quantum Physics · Physics 2023-04-25 Danilo Triggiani , Giorgos Psaroudis , Vincenzo Tamma

In quantum mechanical experiments one distinguishes between the state of an experimental system and an observable measured in it. Heuristically, the distinction between states and observables is also suggested in scattering theory or when…

Quantum Physics · Physics 2015-05-20 Arno Bohm , Peter W. Bryant

To implement quantum information technologies, carefully designed control for preparing a desired state plays a key role. However, in realistic situation, the actual performance of those methodologies is severely limited by decoherence.…

Quantum Physics · Physics 2025-10-02 Kohei Kobayashi

The quantum "Zeno" time of the 2P-1S transition of the hydrogen atom is computed and found to be approximately 3.59 10^{-15}s (the lifetime is approximately 1.595 10^{-9}s). The temporal behavior of this system is analyzed in a purely…

Quantum Physics · Physics 2009-10-31 P. Facchi , S. Pascazio