Many quantum algorithms demand a large number of repetitions to obtain reliable statistical results. Thus, at each repetition it is necessary to reset the qubits efficiently and precisely in the shortest possible time, so that quantum computers actually have advantages over classical ones. In this work, we perform a detailed analysis of three different models for information resetting in superconducting qubits. Our experimental setup consists of a main qubit coupled to different auxiliary dissipative systems, which are employed in order to perform the erasure of the information of the main qubit. Our analysis shows that it is not enough to increase the coupling and the dissipation rate associated with the auxiliary systems to decrease the resetting time of the main qubit, a fact that motivates us to find the optimal set of parameters for each studied approach, allowing a significant decrease in the reset time of the three models analyzed.

A fast and scalable scheme for multi-qubit resetting in superconducting quantum processors is proposed by exploiting the feasibility of frequency-tunable transmon qubits and transmon-like couplers to engineer a full programmable superconducting erasing head. We demonstrate the emergence of collective effects that lead to a decoherence-free subspace during the erasing process. The presence of such a subspace negatively impacts the device’s performance and has been overlooked in other multi-qubit chips. To circumvent this issue and pave the way to the device’s scalability, we employ tunable frequency couplers to identify a specific set of parameters that enables us to erase even those states within this subspace, ensuring the simultaneous multi-qubit resetting, verified here for the two-qubit case. In contrast, we show that collectivity effects can also emerge as an ingredient to speed up the erasing process. To end, we offer a proposal to build up integrated superconducting processors that can be efficiently connected to erasure heads in a scalable way.

We studied the thermodynamic properties such as the entropy, heat ($J_Q$), and work ($J_W$) rates involved when an atom passes through a Ramsey zone, which consists of a mode field inside a low-quality factor cavity that behaves classically, promoting rotations on the atomic state. Focusing on the atom, we show that $J_W$ predominates when the atomic rotations are successful, maintaining its maximum purity as computed by the von Neumann entropy. Conversely, $J_Q$ stands out when the atomic state ceases to be pure due to its entanglement with the cavity mode. With this, we interpret the quantum-to-classical transition in light of the heat and work rates. Besides, we show that, for the cavity mode to work as a Ramsey zone (classical field), several photons (of the order of ${10}^6$) need to cross the cavity, which explains its classical behavior, even when the inside average number of photons is of the order of unity.

Classically, wave interference is a phenomenon that can be explained by considering only the waves themselves, that is, without the need to consider the apparatus that monitors or observes them. Thus, in classical theories, interference can only occur between waves of the same nature. In quantum theory, the observed results require a description of the system and its measuring apparatus, which allows us to rethink the explanation of various natural phenomena. In this paper, we consider the ion-trap platform to study the interference of waves with different physical natures, specifically the electromagnetic and mechanical. At first, we drive two lasers onto a single-trapped ion to produce Jaynes-Cummings and Carrier interactions, where we verify that, depending on the phase relationship between the coherent state of the vibrational (mechanical) mode and the Carrier pulse (electromagnetic wave), the interactions enhance or cancel out population transfer to the electronic state of the ion, that works out as our measuring apparatus for those waves. Extending our result to an ion chain, we verify that a precise modulation of the Carrier Rabi frequency and phase (electromagnetic pulse) according to the amplitude of the incoming mechanical coherent state in the ion chain enables creating either constructive or destructive interference with propagating pulses, in which the electronic state of the driven ion is, respectively, populated more and faster, or transparent to both pulse waves, when the information flux behaves as if no external fields are applied. Finally, this new type of controlled interference between waves of different natures allows us to propose new hybrid quantum devices, such as transistors or filters of wave packets, where photonic (phononic) pulses control the passage of phononic (photonic) waves.