The development of efficient techniques to cool quantum systems has been
instrumental for the emergence of quantum technologies. Preparing a many-body quantum system in a pure target state is, for example, a prerequisite for its use to study complex interactions or implement quantum computations. State preparation needs to work irrespective of the initial state of the quantum system and thus...
Optical Bloch Equations (OBEs) describe the dynamics of atoms that are classically driven on the one hand and coupled to thermal baths on the other, situations ubiquitous in quantum optics, quantum thermodynamics and quantum technologies. OBEs have given rise to consistent thermodynamic analyses, where work (heat) flows from the drive (the bath), yet, in these descriptions, the role played...
Developing a quantum computer is the subject of intense academic and industrial research, due to its promise to solve classically intractable problems. As a consequence, quantum computing is developing rapidly, with recent advances suggesting the feasibility of quantum error correction on a large scale [1]. As with any nascent technology though, many questions remain, regarding the engineering...
Kinetic Uncertainty Relations (KURs) impose fundamental limits on the precision of quantum transport observables by linking signal-to-noise ratios to system activity, a measure of the rate of particle exchange between the system and its environment. While KURs are well-defined in weak coupling regimes, where particle-like behavior dominates, extending these relations to strong coupling regimes...
Commercially viable quantum annealers have proven as reliable tools to seek the groundstates of disordered many body systems mappable to an Ising spin-glass Hamiltonian. An advantage over simulated annealing techniques is given by the intrinsic quantum nature of the spins (superflux qubits) which, thanks to a transverse magnetic field, can more easily and quickly escape metastable...
The Unit Commitment problem (UC) is a well known problem in the context of energy engineering and optimization. Generally described as a family of optimization problems where the energy production of some generators is coordinated based on an objective function, typically the minimization of costs or maximization of revenue. There exist many different versions that take into consideration one...
We present a cooperative protocol to charge quantum spin networks up to the highest-energy configuration, in terms of the network's magnetization. The charging protocol leverages spin-spin interactions and the crossing of a phase transition's critical point to achieve superextensive charging precision.
The cooperative protocol guarantees a precision advantage over any local charging protocol...
Whereas correlations among the constituent parts of a quantum system are often described from an information theoretical perspective, Quantum Thermodynamics provides an alternative framework for the certification and quantification of entanglement in terms of potential work extraction.
In this work we investigate the relationship between separability and ergotropic gap in...
While quantum measurements have been shown to constitute a resource for operating quantum thermal machines, the nature of the energy exchanges involved in the interaction between system and measurement apparatus is still under debate. In this work, we show that a microscopic model of the apparatus is necessary to unambiguously determine whether quantum measurements provide energy in the form...
Quantum computers can offer dramatic speed-ups over their classical counterparts for certain problems. However, noise remains the biggest impediment to realizing the full potential of quantum computing. While the solution to this challenge has been known for almost 30 years with the theory of quantum error correction, a large scale realization of fault tolerance is still pending. What can one...
One of the main tasks of quantum information processing is generating, manipulating, and using quantum resources. Prominent examples of such resources are quantum entanglement and quantum secret key, which are planned to be used in future quantum networks, e.g., for distributed quantum computing and secret communication, respectively. In these networks, quantum resources will be distributed...
Quantum Computing (QC) is undergoing a high rate of development, investment and research devoted to its improvement. However, before one can decide how to improve something, it is first necessary to define the criteria for success: what are the metrics or statistics that are relevant to the problem and the domain of use? As well as computational metrics, understanding resource requirements is...
Adopting a long-term view, the presentation shows how recent scientific progress in scaling quantum computing is bringing new solutions and new questions on the energetics of these systems, particularly when considering fault-tolerant quantum computing roadmaps.
It starts with refining the definition of an energetic quantum advantage, laying out the interconnection between the economics of...
This roundtable will explore the role of quantum science and technology in energy management today. Can quantum technologies make a tangible impact now, or are they still years away from practical application? Is industry’s influence on academic research driving progress or limiting fundamental exploration? Our panel—featuring voices from across the sector—will examine these pressing questions...
As quantum technologies advance, it will be important to have methods to minimize their resource consumption without impact-ing their performance. Here, we show how to use experimental data to build and optimize a system-level (full-stack) model of a quantum computer, within the Metric-Noise-Resource approach [1]; a model that contains everything from the qubits to the end-user. We use it to...
In a world with finite resources where energy demands outgrow energy generation, it is crucial to estimate how much energy quantum networks will consume prior to their deployment. Such a study can reveal limiting factors for future implementations of networks, or even show the energetic advantages of certain quantum technologies over classical ones.
This work presents the foundations of a...
We carried out a quantum thermodynamic analysis of linear versus non-linear interactions in bosonic systems (phonon, photons, etc). We show that linear dynamics (e.g. linear optics) imposes a relation that is more general than the second law of thermodynamics: for modes undergoing a linear evolution, the full mean occupation number, i.e., the photon number for optical modes, does not...
The development of fast and efficient quantum batteries is crucial for the prospects of quantum technologies. We show that both requirements are accomplished in the paradigmatic model of a harmonic oscillator strongly coupled to a highly non-Markovian thermal reservoir [1]. At short times, a dynamical blockade of the reservoir prevents the leakage of energy towards its degrees of freedom,...
Finite-time thermodynamic transformations typically lead to the generation of energetic coherence in the out-of-equilibrium state of a quantum system; indeed, it is possible to identify a contribution to the irreversible entropy production that is due to coherence generation.
On the other hand, coherence is connected also to the non-adiabaticity of a processes, for which it gives the...
The conductance properties of nanojunctions connected to macroscopic electrodes can be explored through quantum transport calculations that employ non-equilibrium Green's functions (NEGF) alongside density functional theory (DFT). When these systems exhibit electron spin polarization, the theoretical analysis often incorporates spin-polarized or unrestricted DFT. In this contribution, we...
The operation of quantum logical devices is necessarily accompanied by irreversibility and therefore dissipation. In practice, this leads to temperature fluctuations in the device and its immediate environment, which can lead to decoherence and fidelity reduction. Measuring the time-resolved temperature fluctuations in a heat absorber then allows estimating the timing and the magnitude of the...
We investigate quantum energy harvesters—systems designed to convert an external quantum source, such as an electromagnetic potential, into useful work, in the form of a measurable electric current. The latter can be utilized to power thermal machines or stored in a quantum battery. Our study focuses on multimode continuous-variable (CV) quantum systems, which provide a natural framework for...
In 2023, we published “The Emergence of Quantum Energy Science,” which laid out how quantum principles well-known in the realm of Quantum Information Science have been put to use in various energy fields, including solar cell engineering, batteries, and nuclear engineering [1]. Since then, our focus has remained on nuclear applications, collecting theoretical and experimental evidence that...
This talk will review recent applications of quantum machine learning to problems in high energy particle physics motivated by the analysis of data from the Large Hadron Collider at CERN, Geneva. Typical tasks include the classifications of jets as quarks or gluons; the classification of calorimeter clusters as electrons or photons; generative modelling of fragmentation and hadronization in...
This roundtable will examine the challenges and opportunities of investing in and regulating quantum energy research. It will bring together experts from diverse sectors, including private investors and public funding bodies. The discussion will highlight key insights, share lessons learned, and explore future directions for advancing the field. Prof John Goold (Trinity College Dublin) will...
In triplet-triplet annihilation (TTA) the molecular energy of two photons is pooled and emitted as fluorescence of a single photon of higher energy. TTA is a promising means of accessing solar irradiance below the silicon bandgap and surpassing the thermodynamic limit for single-junction solar cells. In addition, TTA allows the output light wavelength to be tailored to a specific application...
From a thermodynamic viewpoint, thermoelectric systems are akin to heat engines producing electricity through direct conversion of heat into electrical power. Since the conduction electron gas is the system's working fluid, its properties influence the energy conversion efficiency. Here, we study thermoelectric energy conversion close to an electronic phase transition, focusing on the...
By leveraging quantum mechanical effects such as quantum coherence and entanglement, physical systems can be engineered to exhibit superextensive properties that scale greater than the sum of their parts. This offers distinct advantages over classical technologies and ushers in a desperately needed wave of energy-efficient quantum devices.
Here we present the experimental realisation and...
Quantum batteries, which store and transfer energy at the quantum level, have attracted significant interest for their potential applications in energy-efficient quantum technologies. Previous studies [1,2] demonstrated that an exciton could be stored indefinitely in a symmetry-protected dark state of an open quantum battery model, preventing environment-induced losses. However, an open...
Quantum batteries, quantum systems for energy storage, have gained interest due to their potential scalable charging power density. A quantum battery proposal based on the Dicke model has been explored using organic microcavities, which enable a cavity-enhanced energy transfer process called superabsorption. However, energy storage lifetime in these devices is limited by fast radiative...
When placing an organic material inside an optical cavity, molecular and cavity mode excitations can hybridize into polaritons that provide the coupled system with new, sometimes enhanced, photochemical properties [1]. However, the mechanism by which the light-matter interaction changes the photochemistry of the molecules, remains unknown. Here, using molecular dynamics computer simulations,...
2D electronic spectroscopy (2DES) techniques have become increasingly popular due to their ability to track ultrafast coherent and non-coherent processes in real time [1]. 2DES has garnered significant attention for its role in studying energy and charge transport in complex systems (from biological light-harvesting proteins [2] to solid-state materials [3]), where it has revealed unexpected...
Energy transfer reactions underpin many light-harvesting processes, and their analog quantum simulation can reveal principles for optimal material design. Trapped ion platforms—noted for their coherence and programmability—map naturally onto charge transfer (CT) and vibrationally assisted exciton transfer (VAET) models by tailoring Hamiltonian interactions between the ions’ native spin and...
The density matrix renormalization group was formulated three decades ago to compute the ground state of interacting one dimensional systems. Since then, tensor network methods have grown into an all-encompassing toolbox of algorithms for the low-energy physics of many body systems. This includes ground state search, evolution in real and imaginary time, dynamics of open systems, etc....
Bidimensional electronic spectroscopy (2DES)[1] is a nonlinear optical technique that involves the interaction of a sample with a sequence of three ultrafast pulses, each separated by a precisely controlled delay. The resulting third-order signal is collected in a phase-matching direction. 2DES has proven to be an exceptional tool for probing quantum coherence in light-harvesting systems...
Thermometry of superconductive qubit attracts special attention due to prospects of monitoring temperature with minimal invasion, properties of quantum systems with high accuracy at extremely low temperatures [1]. Studies of qubit thermalization process shed light onto interaction between the qubits and their effective environment, contributing to the field of open quantum systems and quantum...
Photoinduced Excited State Proton Transfer (ESPT) is characterized by a transfer of a proton between two moieties of a molecule when the system is photoexcited, often seen via an exceptionally large (≥ 8000 cm-1) Stokes shift in fluorescence spectra. The efficiency of photoinduced ESPT reactions is critical for the light reactions of photosynthesis and light-driven enzyme biosynthesis [2]....
The implementation of quantum logic in cryogenic quantum computers requires continuous energy supply from room-temperature control electronics. The dependence on external energy sources limits scalability due to control channel density and heat dissipation. Here, we suggest quantum batteries as an intrinsic energy source for quantum computation that facilitates quantum universal gate-set. We...
We are at the verge of the Quantum Technology Revolution: quantum mechanics allows for phenomena that have no classical counterparts and which can be harvested for new technologies. An example of the emerging quantum technologies are quantum batteries (QB), i.e. quantum mechanical systems that can store and transfer energy in a coherent way. While the practical implementation of such devices...
Cooling qubits is challenging task in the development of quantum computers for practical purposes. We consider a target qubit and a qubit machine assisted by a catalyst to achieve catalytic advantage in the thermodynamic process. We show that using a catalyst, one can achieve catalytic advantage in two ways: a) Extending the regime of operation and b) Better cooling performance as compared to...
The transfer of energy from a coherent source (e.g. a laser) to a quantum battery is of significant technological importance. However, a bounded transfer of energy from an incoherent source (e.g. a thermal bath) to a quantum battery, and its storage in a coherent form (active states) is also possible. In this study, we propose a novel approach for using thermal reservoirs for battery charging....
We investigate the performance of a one-dimensional dimerized $XY$ chain as a spin quantum battery. Such integrable model shows a rich quantum phase diagram that emerges through a mapping of the spins onto auxiliary fermionic degrees of freedom. We consider a charging protocol relying on the double quench of an internal parameter, namely the strength of the dimerization, and address the energy...
In this work [1], we explore the concept of a cyclic quantum battery, an idea to harness quantum mechanics to improve energy storage in miniaturized devices. Conventional batteries rely on electrochemical processes, while a quantum battery uses the properties of quantum systems to store and release energy more efficiently. Our goal is to theoretically investigate a feasible model for such a...
We investigate the charging performance of an anisotropic XYZ model of Heisenberg Spin Chain Quantum Battery (HS QB) along with different components of Dzyaloshinskii-Moriya Interaction (DMI) for three cases - short range, long range and infinite range interactions. We find that the presence of DMI enhances the charging power and total stored energy of the QB considered here, when compared to...
The use of Stochastic Schrödinger Equations (SSE) to describe open quantum systems is a well-known class of methods, that can be used as an unravelling scheme of associated Quantum Master Equations and as a starting point to derive new ones. From the perspective of simulating quantum systems in Quantum Computers (QC), one can exploit stochastic averages to implement intrinsically contractive...
Ergotropy, the maximum extractable work via unitary operations, is a fundamental measure of the energetic content of a quantum system. However, its evaluation and the corresponding energy-extraction protocol typically require precise knowledge of the system’s state. In this work, we investigate the minimum energy that can be extracted with a unitary protocol that is independent from any...
In the SU(1,1) interferometer, proposed by Yurke [Physical Review A, 33(6), 4033], beam splitters are replaced by nonlinear elements like optical parametric amplifiers (OPA) to achieve the sensitivity up to the Heisenberg limit. Non-Gaussian operations, like photon addition or subtraction, can further improve its phase sensitivity and robustness against photon loss but at a high implementation...
In recent years, quantum thermometry has emerged as a promising approach for achieving precise temperature measurements at the nanoscale, where classical thermometers fail to perform effectively. Quantum probes, such as single- and two-qubit systems, offer a powerful method for accurately measuring the temperature of a bosonic bath. In this talk, I will discuss how the precision of temperature...
Repeated Interaction Schemes (RIs) or Quantum Collision Models (CMs) are a class of discrete time system-environment models where, in their simplest formulation, the environment is considered as a large collection of identical and independent subunits, called ancillas, and the system-environment dynamics is viewed as a sequence of two-body unitary collisions. Each ancilla can interact only one...
Over the past several decades, there have been dozens of reports of anomalies from hydrogen isotopes embedded at high densities in metal lattices. These anomalies include neutron and charged particle emission, changes in elemental and isotopic composition, and heat generation, suggesting a novel class of nuclear reactions. Because of the low stimulation energies involved, these have been...
A fundamental problem in quantum thermodynamics is to properly quantify the work extractable
from out-of-equilibrium systems. While for closed systems, maximum quantum work extraction is
defined in terms of the ergotropy functional, this question is unclear in open systems interacting
with an environment. The concept of local ergotropy has been proposed, but it presents several
problems,...
Statistical mechanics and information theory share a common ground, giving rise to an intricate relationship. The most famous example of this connection is Landauer’s erasure principle, which gives a bound on dissipated heat required by an irreversible operation. Our goal is to link concepts from quantum thermodynamics and quantum communication to find a fundamental lower bound on the energy...
Quantum computing offers transformative potential for solving energy-related problems in quantum chemistry and material discovery. Among various hybrid quantum-classical algorithms, the Variational Quantum Eigensolver (VQE) has emerged as a versatile tool for calculating molecular ground-state energies with near-term quantum hardware. This study explores the use of advanced techniques,...
Quantum technologies rely on the precise manipulation of delicate quantum states and correlations, which are often vulnerable to the influence of the environment. While dissipation is usually seen as detrimental, we show that a regime of strong dissipation can be harnessed to improve performance and precision (low relative fluctuations) in quantum thermal machines, devices capable of...
Spin defects in diamond have emerged in the last decade as a prominent platform for quantum technological applications, including quantum sensing, communication and computing. More recently, they have been established as a powerful tool for the investigation of fundamental topics such as quantum thermodynamics of nonequilibrium processes at the nanoscale, where quantum coherence and...
Anderson localization (AL) and Many-Body localization (MBL) are dynamical phenomena in which the quantum system fails to dynamically achieve the thermodynamical equilibrium. It is known in literature that, for a quantum spin chain bipartite into two halves, entanglement entropy trend over time serves as characterization for the different phases, that is AL, MBL, and ergodic one. Previous works...
Multilevel quantum system, known as qudits, are the natural generalization of the concept of bits in quantum information. Mastering qudit control can open new avenues in the quantum simulation of complex quantum systems.
I will present a novel scheme based on the use of structured optical beams, dedicated to the control of atomic qudits for quantum simulations.
I will illustrate the...
The transfer of energy among chromophores is a topic of particular interest in the field of physical chemistry and a key to understanding the efficiency of photosynthetic processes. The quantum dynamics underlying transfer processes often stems from an intricate balance between coherent quantum evolution and irreversible dissipative processes, calling for a meaningful partition of the problem...
Bosonic systems with negative Wigner function superposition states are fundamentally witnessing nonlinear quantum dynamics beyond linearized systems and,recently, have become essential resources of quantum technology with many applications. Typically, they appear due to sophisticated combination of external drives,nonlinear control, measurements or strong nonlinear dissipation of subsystems to...
We characterize the measurement sensitivity, quantified by the Quantum Fisher Information (QFI), of a thermometric probe of quantum harmonic oscillator (QHO) strongly coupled to the sample of interest, a bosonic bath at temperature T. For non-equilibrium protocols, in which the probe is measured before reaching equilibrium with the sample, new behavior of the measurement sensitivity arising...
Nonreciprocity, arising from the breaking of time-reversal symmetry, has become a fundamental tool in diverse quantum technology applications. It enables directional flow of signals and efficient noise suppression, constituting a key element in the architecture of current quantum information and computing systems. Here we explore its potential in optimizing the charging dynamics of a quantum...
The precise manipulation of electronic states is at the core of modern information technology and is now poised to also become an integral part of new energy technologies such as quantum batteries. Extending the quantum engineering principles deployed in these contexts to the domain of the nucleus follows naturally and is the focus of our work.
Some of the key principles in nuclear...
We investigate the optimal performance of a theoretical class of stroke heat engines, where the coupling to heat baths is separated from the work extraction process. Furthermore, we focus on minimal engines in which both the number of strokes and the available frequencies in the working body are minimized. For these simplest thermal engines, we developed methods for efficiency optimization,...
Singlet fission (SF) is an electronic transition that in the last decade has been under the spotlight for its applications in optoelectronics, from photovoltaics to spintronics. Despite considerable experimental and theoretical advancements, optimizing SF in materials like multichromophoric systems and molecular crystals remains a challenge, due to the complexity of its analysis beyond...
Quantum thermodynamics defines the ideal quantum thermoelectric, with maximum possible efficiency at finite power output. However, such an ideal thermoelectric has not yet been implemented experimentally. Thus, instead, we consider two thermoelectrics regularly implemented in experiments: (i) a single-level quantum dot and (ii) a potential barrier or quantum point-contact. We model them with...
In 1964, Terhune and Baldwin proposed that nuclei, when arranged in a solid-state lattice, cannot be treated as independent systems but rather as integrated two-level quantum systems indirectly coupled via interaction with the “common electromagnetic and phonon fields.” [1] In 2018, Chumakov et al. demonstrated the superradiant decay of 57Fe nuclei at room temperature, wherein the nuclear...
Quantum batteries (QBs) are emerging as a promising paradigm for energy storage and management at the quantum scale, offering new functionalities in quantum technologies. In this work, we propose that quantum actuators can be interpreted as quantum batteries due to their role in enabling and controlling quantum operations. By leveraging the properties of superconducting qubits, these actuators...
Hydrogen-bonded systems play a crucial role in chemistry, biology, and material sciences, underpinning key processes such as protein folding, molecular recognition, and drug binding. Accurately modeling these non-covalent interactions remains a major challenge as they require a precise description of electron correlation effects. Quantum computing has the potential to improve the study of such...
Levitated objects in ultra-high vacuum offer a new paradigm for free-space optomechanics [1]. In the absence of clamping losses and background gas, an exceptional degree of isolation from the environment can be achieved, enabling quantum optomechanical cooperativities exceeding one even at ambient temperature. Combined with near-Heisenberg-limited position measurements, this has allowed the...
Ergotropy, the maximum extractable energy from a quantum system via cyclic unitary operations, traditionally stems from a semi-classical perspective, where a quantum system, such as an atom, interacts with a classically treated field like a laser. This approach inherently overlooks the key genuine quantum features such as the field statistics, atom-field entanglement, population collapse and...
In the realm of quantum thermodynamics, one of the primary goals is to develop efficient microscopic machines that operate within the quantum regime. Such quantum devices hold promise as tools for cooling quantum processors directly at the microscopic scale. However, they encounter a fundamental challenge: the intrinsic trade-off between power and efficiency in finite-time thermodynamic...
We consider a quantum battery composed of a pair of qubits coupled with an Ising interaction in the usual NMR framework, where the longitudinal applied field is constant and the time-dependent variables controlling the system are the amplitude and phase of the transverse field, and use optimal control to derive fast charging protocols. We study both the cases where the Ising coupling is weaker...
Quantum batteries [1] are quantum systems, such as superconducting qubits or trapped ions, that can store energy after being charged, and eventually deliver it on demand. Despite the increasingly growing interest around these devices [2], nowadays their importance lies in the fact that they lend themselves to being described by a thermodynamic point of view, hence favoring the study of energy...
Quantum walks are the quantum counterparts of classical random walks, and serve as a powerful framework for modeling quantum transport, with various applications in quantum computing and energy transfer. In particular, chiral quantum walks introduce a complex phase in the Hamiltonian, creating a directional bias in the dynamics that can enhance transport efficiency.
In this study, we...
Out-of-equilibrium processes describe a wide plethora of phenomena, from bio-molecular motors in our cells to financial markets and quantum computers. A first universal property they all share is that they necessarily entail a certain amount of dissipation, i.e. thermodynamic resources in the form of entropy production are irreversibly generated. Moreover, they display significant...
Over the last decades, impurity problems have been an invaluable framework to gain significant insight on the physics of many-body quantum systems. The usual setup involves a small quantum system (oftentimes just a single degree of freedom) coupled to a many-body environment. In bosonic quantum fluids, the onset of a drag force experienced by point-like objects is due to collective environment...
Quantum batteries are emerging as highly efficient energy storage devices that can exceed classical performance limits. Although there have been significant advancements in controlling these systems, challenges remain in stabilizing stored energy and minimizing losses due to inevitable environmental interaction. In this paper, we propose a protocol that employs selective weak measurements to...
Scaling ion trap QC to millions of qubits face challenges due to the large number of components required to control the ion and the associated high cost and power consumption. Miniaturization and integration of components in integrated Quantum Processing Units (iQPUs) through microfabrication is a realistic route towards large-scale quantum computing, thanks to the dramatic reduction in size,...
We investigate the dynamical and thermodynamic properties of an open two-qubit Rabi model and a disordered XXZ Heisenberg spin chain using advanced numerical methods. Specifically, we employ the density-matrix renormalization group (DMRG) algorithm for equilibrium conditions and the time-dependent variational principle (TDVP) for out-of-equilibrium scenarios. These methods are applied to...
