We study a quantum Otto engine embedding working substance composed by two-level system interacting with harmonic mode. The physical properties of the are described generalized Rabi model arising in superconducting circuits realizations. show that light-matter correlations reduction during hot bath stage and compression act as resource for enhanced work extraction efficiency respectively. Also, we demonstrate anharmonic spectrum subtance has direct impact on transition from heat into...

Abstract Developing the field of neuromorphic quantum computing necessitates designing scalable memory devices. Here, we propose a superconducting device in microwave regime, termed memcapacitor. It comprises two linked resonators, primary one is coupled to Superconducting Quantum Interference Device, which allows for modulation resonator properties through external magnetic flux. The auxiliary resonator, operated weak measurements, provides feedback ensuring stable behavior. This operates...

We propose a protocol to perform quantum reinforcement learning with technologies. At variance recent results on superconducting circuits, in our current coherent feedback during the process is not required, enabling its implementation wide variety of systems. consider diverse possible scenarios for an agent, environment, and register that connects them, involving multiqubit multilevel systems, as well open-system dynamics. finally implementations this trapped ions circuits. The field...

We introduce the concept of degree quantumness in quantum synchronization, a measure nature synchronization systems. Following techniques from information, we propose number non-commuting observables that synchronize as quantumness. This figure merit is compatible with already existing measurements, and it captures different physical properties. illustrate system consisting two weakly interacting cavity-qubit systems, which are coupled via exchange bosonic excitations between cavities....

We propose the interaction of two quantum memristors via capacitive and inductive coupling in feasible superconducting circuit architectures. In this composed system input gets correlated time, which changes dynamic response each memristor terms its pinched hysteresis curve nontrivial entanglement. sense, concurrence memristive dynamics follow an inverse behavior, showing maximal values entanglement when is minimal vice versa. Moreover, direction followed time by reversed whenever maximal....

We study the entanglement and memristive properties of three coupled quantum memristors. consider memristors based on conductance-asymmetric superconducting interference device architectures that are via inductors. The arranged in two different geometries: linear triangular coupling configurations. obtain a variety correlation measures, including bipartite tripartite negativity. For identical memristors, we find memristivity follow same behavior for case opposite one case. Finally,...

Abstract Shortcuts to adiabaticity provide a flexible method accelerate and improve quantum control task beyond adiabatic criteria. However, their application the fast generation of multi-partite gates is still not optimized. Here we propose reverse-engineering approach design longitudinal coupling between set qubits coupled several field modes, for achieving in photonic or qubit-based architecture. We show that enhancing time at nanosecond scale does with number system components. In...

We study the quantum synchronization between a pair of two-level systems inside two coupled cavities. By using digital-analog decomposition master equation that rules system dynamics, we show this approach leads to both systems. Moreover, can identify in block fundamental elements machine learning protocol, which agent and environment (learning units) interact through mediating system, namely, register. If additionally equip algorithm with classical feedback mechanism, consists projective...

Classical to quantum decoherence transition, an issue existing for incoherent superposition of Bell-diagonal states is studied three dimensional bipartite AB mixed systems. Depending on the initial conditions, dynamics classical and correlations can exhibit a sudden transition between decoherence. This result calculated numerically by using entropic geometric measures correlations. An alternative explanation this effect could be obtained extending A ⊗ B qutrit system pure tripartite C...

Abstract We study quantum state transfer between two qubits coupled to a common bus that is constituted by an ultrastrong light-matter system. By tuning both qubit frequencies on resonance with forbidden transition in the mediating system, we demonstrate high-fidelity swap operation even though thermally populated. discuss possible physical implementation realistic circuit QED scheme leads multimode Dicke model. This proposal may have applications hot information processing within context of...

We study the quantum correlations embedded in open Rabi systems. Specifically, we how correlation depends on coupling strength, number of qubits, and reservoir temperatures. numerically calculate up to three qubits interacting with a single field mode. find that exhibit maximum for given which inversely subsystems temperature. explore this feature affects performance many-qubit Otto heat engine, finding numerical evidence direct correspondence between minimum extractable work qubit-cavity...

We present protocols for the generation of high-dimensional entangled states anharmonic oscillators by means coherent manipulation light-matter systems in ultrastrong coupling regime. Our consider a pair coupled qubit-cavity systems, each to an ancilla qubit, and combine classical pulses plus selection rules imposed parity symmetry. study robustness entangling under dissipative effects. This proposal may have applications within state-of-art circuit quantum electrodynamics.

We propose a method to generate nonclassical states of light in multimode microwave cavities. Our approach considers two-photon processes that take place system composed N extended cavities and an ultrastrongly coupled light–matter system. Under specific resonance conditions, our generates, deterministic manner, product uncorrelated photon pairs, Bell states, W different modes on the Furthermore, numerical simulations show generation scheme exhibits collective effect which decreases time...

We propose how to engineer the longitudinal coupling accelerate measurement of a qubit longitudinally coupled cavity, motivated by concept shortcuts adiabaticity. Different modulations are inversely designed from two methods inverse engineering and counter-diabatic driving, for achieving larger values signal-to-noise ratio (SNR) at nanosecond scale. By comparison, we demonstrate that our protocols outperform usual periodic on pointer state separation SNR. Finally, show possible...

Solving optimization problems using variational algorithms stands out as a crucial application for noisy intermediate-scale devices. Instead of constructing gate-based quantum computers, our focus centers on designing within the analog paradigm. This involves optimizing parameters that directly control pulses, driving states toward target without necessity to compile circuit. In this work, we introduce pulse-based (PBVQO) hardware-level framework. We illustrate framework by external fluxes...

Solving optimization problems using variational algorithms stands out as a crucial application for noisy intermediate-scale devices. Instead of constructing gate-based quantum computers, our focus centers on designing within the analog paradigm. This involves optimizing parameters that directly control pulses, driving states towards target without necessity compiling circuit. In this work, we introduce pulse-based (PBVQO) hardware-level framework. We illustrate framework by external fluxes...

We study quantum state transfer between two qubits coupled to a common bus that is constituted by an ultrastrong light-matter system. By tuning both qubit frequencies on resonance with forbidden transition in the mediating system, we demonstrate high-fidelity swap operation even though thermally populated. This proposal may have applications hot information processing within context of coupling regime interaction.

Multi-mode superconducting circuits offer a promising platform for engineering robust systems quantum computation. Previous studies have shown that single-mode devices cannot simultaneously exhibit resilience against multiple decoherence sources due to conflicting protection requirements. In contrast, multi-mode increased flexibility and proven capable of overcoming these fundamental limitations. Nevertheless, exploring architectures is computationally demanding the exponential scaling...

Qudits, generalizations of qubits to multi-level quantum systems, offer enhanced computational efficiency relative by encoding more information per lattice cell. Utilizing the $d$-level manifold however requires very fast gate operations because higher levels typically suffer from exponentially larger energy level dispersion, and hence stronger decoherence. We present a universal pulse construction quickly generate unitary rotations between any adjacent levels, with same coherent error...

We propose a quantum optimal control framework based on the Pontryagin Maximum Principle to design energy- and time-efficient pulses for open systems. By formulating Langevin equation of dissipative LC circuit as linear problem, we derive optimized with exponential scaling in energy cost, outperforming conventional shortcut-to-adiabaticity methods such counter-diabatic driving. When applied resonator dispersively coupled qubit, these achieve an excellent signal-to-noise ratio comparable...

Based on renewed interest in the shortcut-to-adiabaticity techniques quantum control, we propose a reverse-engineering approach to modulate longitudinal coupling between pair of two-level systems with quantized single-mode resonator. This allows us suppress unwanted transitions time-evolution operator such that system dynamics resemble controlled-phase gate acting qubit subspace at nanosecond scale. The reduced gating time mitigates detrimental effect produced by loss mechanisms all aspects....

We study the feasibility of reaching ultrastrong (USC) and deep-strong coupling (DSC) regimes light-matter interaction, in particular at resonance condition, with a superconducting charge qubit, also known as Cooper-Pair box (CPB). numerically show that by shunting qubit high-impedance LC-circuit, one can maximally reach both USC DSC exceeding classical upper bound $|g|\leq \sqrt{\omega_q\omega_r}/2$ between two harmonic systems frequencies $\omega_q$ $\omega_r$. As an application, we...