@article{Crognaletti2024,

title = {Equivariant Variational Quantum Eigensolver to detect phase transitions through energy level crossings},

author = {Giulio Crognaletti and Giovanni Di Bartolomeo and Michele Vischi and Luciano Loris Viteritti},

doi = {10.1088/2058-9565/ad9be3},

issn = {2058-9565},

year  = {2025},

date = {2025-01-01},

journal = {Quantum Sci. Technol.},

volume = {10},

number = {1},

publisher = {IOP Publishing},

abstract = {Abstract

               Level spectroscopy stands as a powerful method for identifying the transition point that delineates distinct quantum phases. Since each quantum phase exhibits a characteristic sequence of excited states, the crossing of energy levels between low-lying excited states offers a reliable mean to estimate the phase transition point. While approaches like the Variational Quantum Eigensolver are useful for approximating ground states of interacting systems using quantum computing, capturing low-energy excitations remains challenging. In our study, we introduce an equivariant quantum circuit that preserves the total spin and the translational symmetry to accurately describe singlet and triplet excited states in the J

                  1–J

                  2 Heisenberg model on a chain, which are crucial for characterizing its transition point. Additionally, we assess the impact of noise on the variational state, showing that conventional mitigation techniques like Zero Noise Extrapolation reliably restore its physical properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{DiBartolomeo2024b,

title = {Efficient quantum algorithm to simulate open systems through a single environmental qubit},

author = {Giovanni Di Bartolomeo and Michele Vischi and Tommaso Feri and Angelo Bassi and Sandro Donadi},

doi = {10.1103/physrevresearch.6.043321},

issn = {2643-1564},

year  = {2024},

date = {2024-12-00},

journal = {Phys. Rev. Research},

volume = {6},

number = {4},

publisher = {American Physical Society (APS)},

abstract = {We present an efficient algorithm for simulating open quantum systems dynamics described by the Lindblad master equation on quantum computers, addressing key challenges in the field. In contrast to existing approaches, our method achieves two significant advancements. First, we employ a repetition of unitary gates on a set of n system qubits and, remarkably, only a single ancillary bath qubit representing the environment. It follows that, for the typical case of m locality of the Lindblad operators, we reach an exponential improvement of the number of ancilla in terms of m and up to a polynomial improvement in ancilla overhead for large n with respect to other approaches. Although stochasticity is introduced, requiring multiple circuit realizations, the sampling overhead is independent of the system size. Second, we show that, under fixed accuracy conditions, our algorithm enables a reduction in the number of Trotter steps compared to other approaches, substantially decreasing circuit depth. These advancements hold particular significance for near-term quantum computers, where minimizing both width and depth is critical due to inherent noise in their dynamics.

          

            

            

              

                Published by the American Physical Society

                2024

              

            

          },

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gundhi2024,

title = {Decoherence due to the Casimir effect?},

author = {Anirudh Gundhi},

doi = {10.1103/physrevd.110.116001},

issn = {2470-0029},

year  = {2024},

date = {2024-12-00},

journal = {Phys. Rev. D},

volume = {110},

number = {11},

publisher = {American Physical Society (APS)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Braidotti2024,

title = {Amplification of electromagnetic fields by a rotating body},

author = {M. C. Braidotti and A. Vinante and M. Cromb and A. Sandakumar and D. Faccio and H. Ulbricht},

doi = {10.1038/s41467-024-49689-w},

issn = {2041-1723},

year  = {2024},

date = {2024-12-00},

journal = {Nat Commun},

volume = {15},

number = {1},

publisher = {Springer Science and Business Media LLC},

abstract = {AbstractIn 1971, Zel’dovich predicted the amplification of electromagnetic (EM) waves scattered by a rotating metallic cylinder, gaining mechanical rotational energy from the body. This phenomenon was believed to be unobservable with electromagnetic fields due to technological difficulties in meeting the condition of amplification that is, the cylinder must rotate faster than the frequency of the incoming radiation. Here, we measure the amplification of an electromagnetic field, generated by a toroid LC-circuit, scattered by an aluminium cylinder spinning in the toroid gap. We show that when the Zel’dovich condition is met, the resistance induced by the cylinder becomes negative implying amplification of the incoming EM fields. These results reveal the connection between the concept of induction generators and the physics of this fundamental physics effect and open new prospects towards testing the Zel’dovich mechanism in the quantum regime, as well as related quantum friction effects.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}