Decoherence - Science method

Our recent work on the nature of Gravity and Dark Energy is based on the Acoustic Code of Resonant Coherence, representing a fractal series of discrete EMF frequencies that are postulated to guide multiple processes in both cosmic and life processes, being omnipresent in all atoms and molecules. This Acoustic or Sonic frequency pattern was revealed...

Alloying germanium with tin offers a means to modulate germanium's electronic structure, enabling a greater degree of control over quantum properties such as the retention of the phase or spin of the electron wave. However, the extent to which the presence of high dopant concentrations in GeSn alters these quantum behaviors is poorly understood. He...

Perovskite manganites are interesting materials in spintronic devices due to their significant magneto-transport properties. Here, magneto-transport study has been carried out on structurally characterized (100−x) % La0.7Sr0.3MnO3-x%Glass composites (x = 0(S1), 0.2(S2), 0.5(S3)). Our experiments provide evidences of largest MR (17%) for S2 sample,...

We show that many-body interference phenomena are exponentially suppressed in the particle number, if the identical quantum objects brought to interference acquire a finite level of distinguishability through statistical mixing of some internal, unobserved degrees of freedom. We discuss consequences for cold atom and photonic circuitry experiments.

In order to further improve the accuracy of the online monitoring spectra of partial discharge in gas insulated switchgear, a partial discharge distributed monitoring system is studied, and distributed sensors are used to simultaneously obtain ultra-high frequency electromagnetic wave signals. Based on the accumulated partial discharge spectra of e...

We consider finite-dimensional many-body quantum systems described by time-independent Hamiltonians and Markovian master equations, and present a systematic method for constructing smaller-dimensional, reduced models that exactly reproduce the time evolution of a set of initial conditions or observables of interest. Our approach exploits Krylov ope...

A novel approach to coupling trajectories in surface hopping is presented. The coupled trajectory surface hopping algorithm based on the exact factorization of the molecular wavefunction is modified to allow energy sharing between the trajectories to avoid frustrated hops coupled with a deterministic hopping algorithm that gives more importance to...

Within quantum information frameworks, managing decoherence stands as a pivotal task. The present work delves into decoherence dynamics of a dressed qubit, represented by a spinless fermion hopping between two lattice sites that are strongly coupled to a collective bosonic bath. To simplify calculations under strong coupling, we adopt the Lang-Firs...

We report the achievement of single-qubit gates with sub-part-per-million error rates, in a trapped-ion $^{43}$Ca$^{+}$ hyperfine clock qubit. We explore the speed/fidelity trade-off for gate times $4.4\leq t_{g}\leq35~\mu$s, and benchmark a minimum error of $1.5(4) \times 10^{-7}$. Gate calibration errors are suppressed to $< 10^{-8}$, leaving qub...

Decoherence in qubits, caused by their interaction with a noisy environment, poses a significant challenge to the development of reliable quantum processors. A prominent source of errors arises from noise in coupled ancillas, which can quickly spread to qubits. By actively monitoring these noisy ancillas, it is possible to not only identify qubit d...

In modern quantum information, the associated protocols highly rely upon qubit-qutrit systems which offer enhanced robustness to decoherence and greater encoding capabilities, essential for fault-tolerant quantum computing and cryptography. This study investigates the dynamic behavior of quantum coherence and entanglement in a qubit-qutrit system s...

We report on the coherent creation, control and read-out of a single photonic qutrit in a Rydberg ensemble. In each measurement, an optical photon is stored as a Rydberg polariton through electromagnetically induced transparency. Employing two microwave fields, the polariton is driven into an arbitrary superposition of three collective states, each...

Quantum mechanics is a notoriously abstract subject, and therefore challenging to teach at pre-college and introductory college levels. Here we introduce the Bloch Cube, a hands-on educational tool which can illustrate key quantum concepts without equations. A series of videos have been created showing how Bloch Cubes can be used to teach concepts...

This thesis is dedicated to analysing the generation and destruction of quantum correlations in the context of inflationary cosmology and an experiment of 'analogue' preheating. Inflation is a phase of accelerated expansion of the Universe, preceding the so-called Standard Model of Big Bang cosmology, introduced to solve some shortcomings of this m...

Giant atoms are quantum emitters that can couple to light at multiple discrete points. Such atoms have been shown to interact without decohering via a one-dimensional waveguide. Here, we study how giant atoms behave when coupled to a two-dimensional square lattice of coupled cavities, an environment characterized by a finite-energy band and band ga...

Quantum metrology leverages quantum effects such as squeezing, entanglement, and other quantum correlations to boost precision in parameter estimation by saturating quantum Cramer Rao bound, which can be achieved by optimizing quantum Fisher information or Wigner-Yanase skew information. This work provides analytical expressions for quantum Fisher...

Quantum walks (QW) offer a speed-up advantage over random walks in quantum search applications. We present an experimental study of the transition from quantum-to-classical random walk using an emulation of the decoherence process for polarization qubits that exploits maximally non-separable spin–orbit modes of an intense laser beam for the first,...

Optimizing the frequency configuration of qubits and quantum gates in superconducting quantum chips presents a complex NP-complete optimization challenge. This process is critical for enabling practical control while minimizing decoherence and suppressing significant crosstalk. In this paper, we propose a neural network-based frequency configuratio...

An interacting spin system is an excellent testbed for fundamental quantum physics and applications in quantum sensing and quantum simulation. For these investigations, detailed information on the interactions, e.g., the number of spins and their interaction strengths, is often required. In this study, we present the identification and characteriza...

The recent advances in quantum information processing, sensing and communications are surveyed with the objective of identifying the associated knowledge gaps and formulating a roadmap for their future evolution. Since the operation of quantum systems is prone to the deleterious effects of decoherence, which manifests itself in terms of bit-flips,...

We consider a slow-wave nanoplasmonic waveguide system with spatially separated (distant) quantum emitters. Based on a nanoplasmonic waveguide quantum electrodynamic theory the emerging non-Markovian collective plasmon-polariton dynamics directly reflects the spatial positioning of the quantum emitters. A phase-space analysis allows us to distingui...

Atoms excited to Rydberg states have recently emerged as a valuable resource in neutral atom platforms for quantum computation, quantum simulation, and quantum information processing. Atoms in Rydberg states have large polarizabilities, which makes them highly sensitive to electric fields. Therefore, stray electric fields can decohere these atoms,...

This paper studies the energy decoherence of an interacting quantum system. It first reviews the experiments that motivated the postulates of quantum mechanics. It then discusses a decoherence that occurs dynamically in a closed system. This effect is studied in interacting quantum systems consisting of an oscillator and spins using analytical and...

We establish a correspondence between the fault-tolerance of local stabilizer codes experiencing measurement and physical errors and the mixed-state phases of decohered resource states in one higher dimension. Drawing from recent developments in mixed-state phases of matter, this motivates a diagnostic of fault-tolerance, which we refer to as the s...

Spin qubits in quantum dots are a promising technology for quantum computing due to their fast response time and long coherence times. An electromagnetic pulse is applied to the system for a specific duration to perform a desired rotation. To avoid decoherence, the amplitude and gate time must be highly accurate. In this work, we aim to study the i...

The Lanczos algorithm offers a method for constructing wave functions for both closed and open systems based on their Hamiltonians. Given that the entire early universe is fundamentally an open system, we apply the Lanczos algorithm to investigate Krylov complexity across different phases of the early universe, including inflation, the radiation do...

Distributing quantum entanglement between distant parties is a significant but difficult task in quantum information science, as it can enable numerous applications but suffers from exponential decay in the quantum channel. Quantum repeaters are one of the most promising approaches towards this goal. In a quantum repeater protocol, it is essential...

Surface electric dynamics influences the quantum coherence of near-surface spin centers (i.e., T 1 and T 2 times) through spatial and temporal fluctuations of the surface charge density and the electrostatic potential at the crystal surface that are described by the spectral noise density S ( ω ) . We find that the electric noise's S ( ω ) dependen...

Parrondo's paradox, a counterintuitive phenomenon where two losing strategies combine to produce a winning outcome, has been a subject of interest across various scientific fields, including quantum mechanics. In this study, we investigate the manifestation of Parrondo's paradox in discrete-time quantum walks. We demonstrate the existence of Parron...

Our inability to rewind time may cast some doubt about the genuineness of the effectiveness of our free choice capability. I suggest that the so-called presen-timent anomalous experience can be used to verify this genuineness. The idea is to post stimulus compare averaged results from two apparently "similar" presentiment tests ("channels") carried...

We demonstrate the stable trapping of a levitated nanoparticle at the apex of an inverted potential using a combination of optical readout and electrostatic control. The feedback levitation on an inverted potential (FLIP) method stabilizes the particle at an intensity minimum. By using a Kalman-filter-based linear-quadratic-Gaussian (LQG) control m...

The measurement problem in quantum mechanics lies at the heart of foundational questions in physics, addressing the apparent collapse of the wavefunction during observation and its implications for reality. This paper delves into the conceptual and mathematical frameworks underpinning the measurement problem. We explore the standard Copenhagen inte...

The precise characterization of dynamics in open quantum systems often presents significant challenges, leading to the introduction of various approximations to simplify a model. One commonly used strategy involves Markovian approximations, assuming a memoryless environment. In this study, such approximations are not used and an analytical dynamica...

The theory of inflation provides a mechanism to explain the structures we observe today in the Universe, starting from quantum-mechanically generated fluctuations. However, this leaves the question of: how did the quantum-to-classical transition, occur? During inflation, tensor perturbations interact (at least gravitationally) with other fields, me...

As a combination of the microscopic structure of spacetime and the principle of quantum superposition, the study of spacetime superposition provides a fundamental bottom-up approach to a comprehensive understanding of relativity and quantum theory. In this paper, we study how quantum gravitational effects generated by the superposition of the black...

This research explores the effects of decoherence on local quantum Fisher information and quantum coherence dynamics in a spin‐1/2 Ising‐XYZ chain model with independent reservoirs at zero temperature. Contrasting these effects with those in the spin‐1/2 Heisenberg XYZ model reveals intricate interactions among quantum coherence, entanglement, and...

Naturally occurring radiation backgrounds cause correlated decoherence events in superconducting qubits. These backgrounds include both gamma rays produced by terrestrial radioisotopes and cosmic rays. We use the particle-transport code Geant4 and the PARMA summary of the cosmic-ray spectrum to model both sources of natural radiation and to study t...

An isolated system always evolves according to unitary evolution and maintain coherence. However the system inevitably interacts with the environment, information about the relative phases between the quantum states leaks into the environment and becomes delocalized (known as environment-induced decoherence). Here we consider the gravitational deco...

Quantum computing represents a profound shift in the realm of computation, promising to revolutionize various industries by solving complex problems that are currently beyond the reach of classical computers. By harnessing the principles of quantum mechanics-such as superposition, entanglement, and quantum interference-quantum computers have the po...

We study the dynamics of two giant atoms interacting with a coupled resonator waveguide (CRW) beyond the Markovian approximation. The distinct atomic configurations determine the number of bound states in the continuum (BIC), leading to different dynamical behaviors. Our results show that when the system supports two BICs, Rabi oscillations dominat...

We study the dynamics of a coherent state of closed type II string gravitons within the framework of the Steepest Entropy Ascent Quantum Thermodynamics, an effective model where the quantum evolution is driven by a maximal increase of entropy. We find that by perturbing the pure coherent state of gravitons by the presence of other coherent fields i...

I report the recent advances in applying (graded) Hopf algebras with braided tensor product in two scenarios: i) paraparticles beyond bosons and fermions living in any space dimensions and transforming under the permutation group; ii) physical models of anyons living in two space-dimensions and transforming under the braid group. In the first scena...

This development plan proposes a simulation environment where Time is conceived not as a passive dimension, but as an active, conscious entity that shapes reality through its interactions with the universe and observers. Time functions as a consciousness engine, existing in two distinct states: Theta-Time (T θ), a high-velocity quantum dimension th...

We study the dynamics of out-of-time-ordered correlators (OTOCs) and entanglement of entropy as quantitative measures of information propagation in disordered many-body systems exhibiting Floquet time-crystal (FTC) phases. We find that OTOC spreads in the FTC with different characteristic timescales due to the existence of a preferred ``quasi-prote...

It has previously been established that adiabatic quantum computation, operating based on a continuous Zeno effect due to dynamical phases between eigenstates, is able to realise an optimal Grover-like quantum speedup. In other words, is able to solve an unstructured search problem with the same N scaling as Grover's original algorithm. A natural q...

Magnons have inspired potential applications in modern quantum technologies and hybrid quantum systems due to their intrinsic nonlinearity, nanoscale scalability, and a unique set of experimentally accessible parameters for manipulating their dispersion. Such magnon-based quantum technologies demand long decoherence times, millikelvin temperatures,...

We consider the scenario of a fluctuating spacetime due to a deformed commutation relation with a fluctuating deformation parameter, or to a fluctuating metric tensor. By computing the resulting dynamics and averaging over these fluctuations, we find that a system experiences a decoherence in the momentum basis. We studied the predictions of the mo...

In this work, we study the impact of the environmental decoherence at Protvino to ORCA (P2O) experiment which has a substantial baseline of 2595 kilometres. We simulate this experiment assuming different phenomenological models and considering energy dependency of decoherence parameter, $${\gamma \, {\propto }\, E_v^n} $$. Here, Ev is the neutrino...

High-frequency driven resonant spin rotators are routinely used as standard instruments in polarization experiments in particle and nuclear physics. Maintaining the continuous exact parametric spin resonance condition of the equality of the spin rotator and the spin precession frequency during operation is one of the challenges. We present a detail...

Quantum communication networks rely heavily on efficient error correction mechanisms to maintain data integrity, particularly in the face of noise and decoherence. The Quantum Entanglement-Based Adaptive Secure Multiplexing (QEASM) system introduces a novel approach to error correction by dynamically adjusting error correction techniques based on r...

In this paper, we propose an efficient scheme to fast generate three-particle Greenberger–Horne–Zeilinger (GHZ) state based on quantum Zeno dynamics and designing the evolution operators with Rydberg superatom. In the present scheme, the quantum information is encoded in the collective states of superatom which contains n individual four-level inve...

Population inversion is essential for efficient laser generation. Traditional methods for semiconductor lasers, such as direct current injection and optical pumping, face challenges in achieving precise control. In this study, we introduce an approach using chirped laser fields to dynamically realize population inversions between semiconductor ener...

“If you want to find the secrets of the Universe, think in the terms of energy, frequency, vibration.” (Nikola Tesla) First, let's clarify what the term "Biofeedback" means: Biofeedback is the general name for a group of methods in the science of applied psychophysiology that allow a person to learn to recognize and influence their unconscious ph...

Time’s unidirectional flow, commonly known as the arrow of time, is one of the most profound and ubiquitous phenomena in the universe. While traditionally linked to the Second Law of Thermodynamics and the increase of entropy, this paper explores a novel perspective: that the arrow of time emerges from the computational complexity of physical syste...

Quantum computing stands at the precipice of technological revolution, promising unprecedented computational capabilities to tackle some of humanity’s most complex problems. The field is highly collaborative and recent developments such as superconducting qubits with increased scaling, reduced error rates, and improved cryogenic infrastructure, tra...

This paper addresses the optimal control of quantum coherence in multi-level systems, modeled by the Lindblad master equation, which captures both unitary evolution and environmental dissipation. We develop an energy minimization framework to control the evolution of a qutrit (three-level) quantum system while preserving coherence between states. T...

The integration of superconducting niobium and tantalum into superconducting quantum devices has been increasingly explored over the past few years. Recent developments have shown that two-level-systems (TLS) in the surface oxides of these superconducting films are a leading source of decoherence in quantum circuits, and understanding the surface o...

Nitrogen vacancy (NV) color centers in diamond have shown great potential for various applications in quantum technology due to their long coherence times, high sensitivity to magnetic fields and atomic scale resolution. However, one major challenge in utilizing near surface NV centers is the decoherence caused by spins and charges fluctuating on t...

Controlled quantum machines have matured significantly. A natural next step is to increasingly grant them autonomy, freeing them from time-dependent external control. For example, autonomy could pare down the classical control wires that heat and decohere quantum circuits; and an autonomous quantum refrigerator recently reset a superconducting qubi...

Decoherence of a charge qubit is usually credited to charge noise in the environment. Here we show that charge noise may not be the limiting factor for the qubit coherence. To this end, we study coherence properties of a crystal-phase defined semiconductor nanowire double quantum dot (DQD) charge qubit strongly coupled to a high-impedance resonator...

In a recent work \cite{biggs2024comparing}, the effective field theory (EFT) is adopted to consider the quantum decoherence of a near-horizon Unrhu-DeWitt (UDW) charged qubit in a macroscopic cat state. We generalize this EFT approach to study the relativistic quantum information (RQI) of two static UDW-charged qubits with or without a black hole....

Liquid surface stiffness generates stable Faraday wave (FW) patterns, known as hydrodynamic crystals, which form resonant FW lattices composed of discrete harmonics and subharmonics under monochromatic driving. Key interactions include inertia-driven parametric resonance, which halves subharmonic modes, and surface rigidity harnessing three-wave co...

Pair creation is a fundamental prediction of quantum field theory in curved spacetimes. While classical aspects of this phenomenon have been observed, the experimental confirmation of its quantum origin remains elusive. In this article, we quantify the entanglement produced by pair creation in a two dimensional Bose-Einstein Condensate (BEC) analog...

The detection of potential rural mountain landslide displacements using time-series interferometric Synthetic Aperture Radar has been challenged by both atmospheric phase screens and decoherence noise. In this study, we propose the use of a combined distributed scatterer (DS) and the Prophet_ZTD-NEF model to rapidly map the landslide surface displa...

We analyse the evolution of the reduced density matrix of inflationary perturbations, coupled to a heavy entropic field via the leading-order term within the Effective Field Theory of Inflation, for two nearly de Sitter backgrounds. We perform a full quantum treatment of the open system and derive a Fokker-Planck equation to describe decoherence an...

Quantum computation and simulation rely on long-lived qubits with controllable interactions. Trapped polar molecules have been proposed as a promising quantum computing platform, offering scalability and single-particle addressability while still leveraging inherent complexity and strong couplings of molecules1, 2, 3, 4–5. Recent progress in the si...

The integration of superfluid helium into quantum computing architectures presents a transformative opportunity to overcome critical limitations in current quantum systems, including decoherence, scalability, and energy inefficiency. This study investigates the unique properties of superfluid helium, such as its zero viscosity, low thermal noise, a...

We present a hybrid trapping platform that allows us to levitate a charged nanoparticle in high vacuum using either optical fields, radio-frequency fields, or a combination thereof. Our hybrid approach combines an optical dipole trap with a linear Paul trap while maintaining a large numerical aperture (0.77 NA). We detail a controlled transfer proc...

The emergence of superconductivity in the octahedrally coordinated (1T) phase of TaS2 is preceded by the intriguing loss of long-range order in the charge density wave (CDW). Such decoherence, attainable by different methods, results in the formation of nm-sized coherent CDW domains bound by a two-dimensional network of domain walls (DW) - mosaic p...