Article
Optics
Catherine Keele, Alastair Kay
Summary: This article presents an encoding technique that reduces the impact of noise on quantum spin systems driven by Hamiltonian evolution. This technique is widely applicable, particularly in scenarios where full-scale error correction is not feasible. Instead, it can be implemented with a small number of qubits and still result in noticeable improvements in operation fidelity. The encoding scheme is easy to implement, flexible in terms of Hamiltonian selection, and close to optimal.
Article
Chemistry, Physical
Thomas M. Fuchs, Rolf Schaefer
Summary: The magnetic double deflection experiments reveal the impact of nuclear spins on electron spin coherence in isolated AlSn12 clusters, and discuss the superatomic response of nuclear spins in the endohedral cage clusters. By varying the concentration of nuclear spins in the tin cage using isotopically enriched tin samples, the study delves into hyperfine interaction, nuclear spin statistics, and spin dynamics. Furthermore, it is demonstrated that state-interference in the multistate Landau-Zener system AlSn12 explains the significant increase in spin decoherence with the presence of one or two nuclear spins in the cluster.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Optics
G. Mouloudakis, T. Ilias, P. Lambropoulos
Summary: In this work, a recursive method for calculating the wave function of an XX spin chain is presented. The method is based on the time-dependent Schrodinger's equations and allows for closed-form solutions of the transformed amplitudes. The results demonstrate the system's dynamics and state-transfer properties for various parameter combinations, with detailed comparisons of Lorentzian and Ohmic reservoirs.
Article
Physics, Multidisciplinary
Alejandro Ferron, Pablo Serra, Omar Osenda
Summary: The dynamical behavior of quantum state in different quantum spin chains is analyzed when the initial state belongs to the one excitation subspace. The results show that inhomogeneous chains can transfer single excitations with near-perfect fidelity for two different spin chain Hamiltonians.
Article
Materials Science, Multidisciplinary
Y. del Castillo, J. Fernandez-Rossier
Summary: In this paper, we propose a protocol to certify the existence of entanglement in artificial on-surface atomic and molecular spin arrays using electron spin resonance carried by scanning tunnel microscopy (ESR-STM). By combining ESR-STM with atomic manipulation, the spin susceptibilities of surface-spin arrays can be measured, enabling the certification of entanglement.
Article
Chemistry, Multidisciplinary
Soo-hyon Phark, Yi Chen, Hong T. T. Bui, Yu Wang, Masahiro Haze, Jinkyung Kim, Yujeong Bae, Andreas J. J. Heinrich, Christoph Wolf
Summary: Scanning-tunneling microscopy (STM) combined with electron spin resonance (ESR) has enabled single-spin spectroscopy with nanoelectronvolt energy resolution and angstrom-scale spatial resolution. In this study, we demonstrate double electron-electron spin resonance spectroscopy in an STM for two coupled atomic spins by simultaneously and independently driving them using two continuous-wave radio frequency voltages. Our technique allows for quantum-coherent multi-spin sensing, simulation, and manipulation in engineered spin structures on surfaces.
Article
Physics, Multidisciplinary
Pai Peng, Chao Yin, Xiaoyang Huang, Chandrasekhar Ramanathan, Paola Cappellaro
Summary: Periodically driven Floquet quantum systems can enter a long-lived prethermal regime at high driving frequencies, with an exponentially slow heating rate. Experimental observation of prethermalization and other properties of Floquet systems demonstrate the potential for realizing non-trivial Floquet phases of matter.
Article
Optics
Devvrat Tiwari, Shounak Datta, Samyadeb Bhattacharya, Subhashish Banerjee
Summary: In this article, we derive the dynamics of a two-qubit system interacting with spin baths composed of qubits in a thermal state. We analyze the non-Markovian nature of the two qubit dynamics and observe the evolution of quantum correlations under the influence of environmental interaction. We also compare the exact two-qubit dynamics with a locally acting central spin model in a spin bath. This work is important for realizing non-Markovian heat engines and other quantum thermal devices.
Article
Physics, Fluids & Plasmas
Kevissen Sellapillay, Alberto D. Verga
Summary: The study introduces a model of quantum walk on a graph where a particle interacts with spins on edges, leading to rich dynamics and entanglement properties. In the case of a one-dimensional lattice, a Landau-Lifshitz equation describing spin precession is recovered in the continuum limit. The entanglement of asymptotic states follows a volume law for most parameters.
Article
Physics, Multidisciplinary
Pablo Serra, Alejandro Ferron, Omar Osenda
Summary: This study explores the near-perfect quantum state transfer in spin chains with site dependent exchange coefficients for Hamiltonians with nearest neighbors XXZ type interactions without external control. The strength of interactions is obtained through a global optimization method, and the relationship between arrival time and interaction strength arises naturally when data collapse techniques are used for analysis. The arrival times achievable are competitive for moderate chain lengths, and the stability of spin chains against static perturbations is also examined.
Article
Physics, Applied
Feifei Zhou, Xueying Zhou, Zhiyi Hu, Yumeng Song, Ting Zhang, Bing Chen, Nanyang Xu
Summary: Detecting and imaging nuclear spins in diamond is essential for spin-based quantum information processing. Previously, a deep-learning-based algorithm was developed and used in a cryogenic nitrogen-vacancy center experiment. In this study, we improve the method by using a traversal periodic-signal identification approach before the deep-learning processing, enabling the separation of low-resolution DD spectra with overlapped peaks. The improved method shows promising results in room-temperature experiments where spectra are often broadened with temperature.
APPLIED PHYSICS LETTERS
(2022)
Article
Mechanics
Vir B. Bulchandani, Sarang Gopalakrishnan, Enej Ilievski
Summary: This review summarizes recent advances in understanding anomalous transport in spin chains, particularly through the lens of integrability. Numerical methods based on tensor-network techniques have revealed anomalous transport in many canonical integrable spin chains, such as the Heisenberg model. The framework of generalized hydrodynamics has been extended to explain some of the underlying mechanisms of anomalous transport, with discussions on similarities and differences with other contexts. Further, potential transport anomalies in systems with emergent or approximate integrability are briefly reviewed, with ongoing research on anomalous transport and dynamics.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Chemistry, Multidisciplinary
Anton Kirch, Toni Baerschneider, Tim Achenbach, Felix Fries, Max Gmelch, Robert Werberger, Chris Guhrenz, Ausra Tomkeviciene, Johannes Benduhn, Alexander Eychmueller, Karl Leo, Sebastian Reineke
Summary: Wavelength-discriminating systems, which are typically bulky benchtop instruments, can now be replaced by lightweight and flexible single-pixel devices. In this study, a device based on room-temperature phosphorescence is proposed, which can convert wavelength information into the time domain with high resolution. The device, made of organic room-temperature phosphors and colloidal quantum dots, tracks the afterglow intensity of the material to measure the wavelength.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Christian Eidecker-Dunkel, Peter Reimann
Summary: Allosterism traditionally refers to local changes in an extended object, but this study shows that such effects can also occur in simple quantum many-body systems, such as a spin chain. Introducing an impurity at one end of the chain leads to significant changes in the observable behavior near the other end, while the region in between remains largely unaffected.
Article
Quantum Science & Technology
Ivana Dimitrova, Stuart Flannigan, Yoo Kyung Lee, Hanzhen Lin, Jesse Amato-Grill, Niklas Jepsen, Ieva Cepaite, Andrew J. Daley, Wolfgang Ketterle
Summary: By manipulating the spin states of ultracold atoms in an optical lattice system, a transition from a fully magnetized state to a correlated zero-magnetization state has been achieved, and the formation of correlations has been demonstrated. These findings highlight the potential and challenges for preparing many-body eigenstates of spin Hamiltonians through adiabatic preparation protocols.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Thilo Hahn, Jacek Kasprzak, Pawel Machnikowski, Tilmann Kuhn, Daniel Wigger
Summary: The physics of two-dimensional semiconductors has been revitalized with the discovery of transition metal dichalcogenides, where excitons dominate the optical response. Utilizing the Bloch equation model and analyzing four-wave mixing signals have allowed for the understanding of exciton coherence and polarization dynamics in these systems. It has been shown that the characteristics of nonlinear signals vary in time and spectrum when different numbers of pulses are used for excitation.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Kamil Korzekwa, Matteo Lostaglio
Summary: The study shows that quantum dynamics can simulate classical processes that require memory, with advantages in cost, and that Markovian master equations with quantum controls can access more classical states compared to those with classical controls, potentially leading to advantages in cooling protocols.
Article
Physics, Mathematical
Grzegorz Rajchel-Mieldzioc, Kamil Korzekwa, Zbigniew Puchala, Karol Zyczkowski
Summary: The Birkhoff polytope B-d, consisting of bistochastic matrices of order d, is important for various areas of research. We introduce the set L-d of bracelet matrices to study unistochasticity and prove some properties. We analyze the spectra of unistochastic matrices arising from circulant unitary matrices and fully characterize the set of circulant unistochastic matrices for small dimensions.
JOURNAL OF MATHEMATICAL PHYSICS
(2022)
Article
Optics
Johann A. Preuss, Daniel Groll, Robert Schmidt, Thilo Hahn, Pawel Machnikowski, Rudolf Bratschitsch, Tilmann Kuhn, Steffen Michaelis De Vasconcellos, Daniel Wigger
Summary: This study demonstrates coherent state manipulation of a single color center in hexagonal boron nitride (hBN) and investigates the coupling between the electronic system and phonons. The results reveal the application of quantum control techniques in both phonon-assisted and resonant excitation, paving the way for ultrafast phonon quantum state control on the nanoscale and hybrid quantum technologies.
Article
Computer Science, Information Systems
Kamil Korzekwa, Zbigniew Puchala, Marco Tomamichel, Karol Zyczkowski
Summary: We analyze the problem of encoding classical information into different resources of a quantum state, considering a general class of communication scenarios. For any state, we find upper bounds on the number of messages that can be encoded using the operations, as well as matching lower bounds in the case of a specific resource destroying map. In the asymptotic setting, our bounds provide an operational interpretation of resource monotones.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Physics, Multidisciplinary
Kamil Korzekwa, Matteo Lostaglio
Summary: In this study, we present a rigorous approach to algorithmically characterize the complete set of energy occupations of a quantum system accessible from a given initial state through weak interactions with a heat bath. The method can be used to solve complex optimization problems in non-equilibrium setups and provides explicit elementary control sequences for optimal transformations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Rafal A. Bogaczewicz, Pawel Machnikowski
Summary: This paper develops a general theory for resonance fluorescence (RF) in the low excitation limit and investigates the influence of two important types of noise processes on the RF spectrum. The study shows that different classes of noise affect the RF spectrum in a characteristic way, and the spectrum carries information about the noise characteristics present in the physical system.
NEW JOURNAL OF PHYSICS
(2023)
Article
Quantum Science & Technology
Daniel Groll, Fabian Paschen, Pawel Machnikowski, Ortwin Hess, Daniel Wigger, Tilmann Kuhn
Summary: This work explores the efficient light-scattering properties of a single-photon emitter and the appearance of characteristic sidebands in resonance fluorescence spectra when interfaced with an arbitrary phonon quantum state, and how they can be utilized for acousto-optical transduction.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Physics, Fluids & Plasmas
A. de Oliveira Junior, Jakub Czartowski, Karol Zyczkowski, Kamil Korzekwa
Summary: The second law of thermodynamics introduces an asymmetry in the flow of events, known as the thermodynamic arrow of time. This leads to an ordering of the system's state space into past, future, and incomparable regions. In this study, we analyze the structure of thermal cones, which represent the states that a given state can evolve to (future thermal cone) or evolve from (past thermal cone) thermodynamically. We provide explicit constructions of the past thermal cone and the incomparable region for a classical system interacting with a heat bath, and analyze their behavior based on thermodynamic monotones.
Article
Materials Science, Multidisciplinary
Karol Kawa, Tilmann Kuhn, Pawel Machnikowski
Summary: In this study, we analyze the optically driven dynamics of a qubit implemented on a singlet-triplet subspace of two-electron states in a self-assembled quantum dot molecule. We quantitatively characterize the imperfections of the qubit operation and study the effects of decoherence. We identify the most favorable conditions for quantum control in the two optical control schemes.
Article
Physics, Fluids & Plasmas
Tanmoy Biswas, A. de Oliveira Junior, Michal Horodecki, Kamil Korzekwa
Summary: This paper derives a version of the fluctuation-dissipation theorem within a resource-theoretic framework, providing a connection between the response of a system subject to perturbation and the fluctuations associated with observables in equilibrium. The results enable the optimal performance analysis of thermodynamic protocols for quantum states with coherence between different energy eigenstates.
Article
Optics
Matteo Lostaglio, Kamil Korzekwa
Summary: This article presents a framework that overcomes the limitations of current dynamical and information theory approaches in quantum thermodynamics. The framework provides a complete set of generalized entropy production inequalities for non-equilibrium transformations, and can be simplified to a verifiable set of constraints. Importantly, the framework is constructive, returning explicit protocols for any allowed transformation.
Article
Quantum Science & Technology
Hakop Pashayan, Oliver Reardon-Smith, Kamil Korzekwa, Stephen D. Bartlett
Summary: Researchers present two classical algorithms for simulating universal quantum circuits, with each algorithm performing best in different parameter regimes. The ESTIMATE algorithm provides an estimate of measurement outcome probabilities with a specific precision, while the COMPUTE algorithm calculates probabilities to machine precision.
Article
Materials Science, Multidisciplinary
Karol Kawa, Pawel Machnikowski
Summary: In this study, we investigate the spread of correlations in a one-dimensional lattice system with high on-site energy disorder and long-range couplings. We find that the increase in correlation between two nodes exhibits three phases and we also obtain an approximate solution of the model valid in the limit of strong disorder.
Article
Physics, Multidisciplinary
Daniel Wigger, Matthias Weiss, Michelle Lienhart, Kai Mueller, Jonathan J. Finley, Tilmann Kuhn, Hubert J. Krenner, Pawel Machnikowski
Summary: This research combines theory and experiment to demonstrate the characteristic dynamics between phonons and photons. By controlling the detuning of the laser, the blinking dynamics of different sidebands can be manipulated. The use of the SAW method allows for achieving the ideal frequency range and obtaining simultaneous temporal and spectral resolution close to the fundamental time-bandwidth limit.
PHYSICAL REVIEW RESEARCH
(2021)
