Article
Physics, Multidisciplinary
Xin Zhu, Jia-Hao Lue, Wen Ning, Fan Wu, Li-Tuo Shen, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This study generalizes the dynamic framework for criticality-enhanced quantum sensing by the quantum Rabi model to its anisotropic counterpart and derives the corresponding analytical expressions for the quantum Fisher information. The results show that the contributions of the rotating-wave and counterrotating-wave interaction terms are symmetric at the limit of the infinite ratio of qubit frequency to field frequency, and the quantum Fisher information reaches a maximum for the isotropic QRM. At finite frequency scaling, the study analytically derives the inverted variance of higher-order correction and finds that it is more affected by the rotating-wave coupling than by the counterrotating-wave coupling.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Optics
Yu-Qing Shi, Lei Cong, Hans-Peter Eckle
Summary: We investigate the entanglement features in the interacting system of a quantized optical field and a two-level system, known as the asymmetric quantum Rabi model (AsymQRM). Intriguing entanglement resonance valleys and peaks are found with the increase of the coupling strength and driving amplitude. The entanglement resonance is caused by the avoided level crossing of the associated eigenenergies. In contrast to the quantum Rabi model, the entanglement of the AsymQRM collapses to zero in the strong coupling regime unless a specific condition is met. Our analysis reveals that this entanglement reappearance is induced by the hidden symmetry of the AsymQRM. Our results provide insightful understanding of the AsymQRM and have importance in exploring hidden symmetry and preparing photon-atom entanglement in light-matter coupled systems.
Article
Optics
L. O. Castanos-Cervantes
Summary: The article discusses the quantum Rabi model as an open system with dissipation, dephasing, and sinusoidal qubit driving, exploring how changing to an interaction picture and adjusting the driving strength can affect the system dynamics. The driving has two effects on the qubit, changing the transition frequency and reducing dephasing.
Article
Physics, Multidisciplinary
Yu-Yu Zhang, Zi-Xiang Hu, Libin Fu, Hong-Gang Luo, Han Pu, Xue-Feng Zhang
Summary: Studying the quantum Rabi triangle system revealed the emergence of a chiral phase and associated phase transitions, with potential implications for the study of artificial magnetic fields and light-matter coupling systems. This model may offer new insights and applications in the development of various quantum technologies.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Vladimir V. Mangazeev, Murray T. Batchelor, Vladimir V. Bazhanov
Summary: The asymmetric quantum Rabi model exhibits level crossings in the eigenspectrum for specific values of the bias parameter, which are expected to be associated with hidden symmetry of the model. The origin of this hidden symmetry is established by finding operators that commute with the AQRM Hamiltonian at these special values, providing a construction for studying similar level crossings in other related light-matter interaction models.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Editorial Material
Physics, Multidisciplinary
Daniel Braak, Murray T. Batchelor, Qing-Hu Chen
Summary: We discuss the elementary errors in Zhang's claimed exact solution of the quantum Rabi model in his paper published in New Journal of Physics in 2021. It is found that the erroneous solution is nothing more than the combined solution of the simplified Jaynes-Cummings and anti-Jaynes-Cummings models obtained by neglecting terms in the model Hamiltonian.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Gaoke Hu, Maoxin Liu, Xiaosong Chen
Summary: We introduce an eigen microstate approach (EMA) to describe quantum phase transition without the knowledge of the order parameter. The validity of EMA is demonstrated using the quantum Rabi model (QRM), where the critical point, critical exponents, and scaling functions of the superradiant phase transition are obtained through analytical and numerical calculations. The condensation of a specific eigen microstate is suggested to interpret a new phase emergency. Further studies can apply the EMA to more complex quantum phase transition problems where order parameters cannot be easily defined.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Quantum Science & Technology
Lei Chen, Xing-Wei An, Tong-Hui Deng, Zhi-Rong Zhong
Summary: In this paper, an efficient method for achieving a multimode quantum Rabi model in a strong-coupling cavity optomechanical system is proposed. The proposed method shows that by adjusting a bichromatic laser to red- and blue-sideband excitations, the interaction between the cavity mode and the vibrational modes can be treated as a multimode quantum Rabi model under the single-photon strong-coupling regime. The theoretical analysis demonstrates the possibility of achieving entangled states of two vibrational modes in the two-mode quantum Rabi model, which is further validated through numerical simulations.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Physics, Multidisciplinary
Zu-Jian Ying, Simone Felicetti, Gang Liu, Daniel Braak
Summary: The quantum Rabi model with linear coupling exhibits a second-order phase transition at zero mode frequency, enhancing quantum metrology in few-body systems. However, the inclusion of a nonlinear coupling term in the model leads to a first-order-like phase transition at finite frequency, resulting in higher measurement precision and avoiding the detrimental slowing-down effect near the critical point. When a bias term is added, the system can be used as a fluxmeter or magnetometer in circuit QED platforms.
Article
Physics, Multidisciplinary
Q-X Mei, B-W Li, Y-K Wu, M-L Cai, Y. Wang, L. Yao, Z-C Zhou, L-M Duan
Summary: Quantum simulation is an important tool for studying strongly correlated many-body systems. The Rabi-Hubbard model, a hybrid of two fundamental models in quantum optics and condensed matter physics, demonstrates rich physics through local spin-boson interactions and long-range boson hopping competition. Experimental realization of the Rabi-Hubbard model using up to 16 trapped ions allowed for controlled study of its equilibrium properties and quantum dynamics, with verification of the model's predictions through theoretical and experimental comparisons.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Zi-Min Li, Devid Ferri, Murray T. Batchelor
Summary: A variational wave function model has been proposed to describe the ground state of the asymmetric quantum Rabi model, which shows significant improvement over existing approximations in various parameter regimes, especially with arbitrary bias.
Article
Physics, Multidisciplinary
Jingwen Yang, Zhicheng Shi, Zhen-Biao Yang, Li-tuo Shen, Shi-Biao Zheng
Summary: Quantum phase transition and entanglement in the Rabi model with squeezed light were investigated. A special unitary-transformation method was found to remove nonintegrable squeezing and counter-rotating wave interactions when the qubit frequency is close to the field frequency. The analytical ground state agrees well with the numerical solution. It was demonstrated that the ground state exhibits a first-order quantum phase transition induced linearly by the squeezed light. This quantum phase transition does not require multiple qubits or an infinite ratio of qubit frequency to field frequency, addressing a critical problem in the theory and experiment of the Rabi model. As the qubit-field coupling strength increases, the ground-state entanglement reaches its maximum value at the critical point.
Article
Physics, Multidisciplinary
Cid Reyes-Bustos
Summary: This paper derives an explicit formula for the heat kernel of the asymmetric quantum Rabi model and extends the method to the symmetry-breaking QRM model. In addition to the heat kernel formula, the paper also provides formulas for the partition function and the Weyl law for the distribution of eigenvalues.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Multidisciplinary
Tian Ye, Chen Wang, Qing-Hu Chen
Summary: We investigate the quantum phase transition in the dissipative anisotropic quantum Rabi model using the quantum dressed master equation. We reveal the impact of giant photon-bunching behavior on the first-order quantum phase transition through numerical and analytical analysis. The observed two-photon statistics can be well described analytically within a few lowest eigenstates at low temperature. Moreover, significant photon-bunching features are generally exhibited at deep-strong qubit-photon coupling, which is lacking in the dissipative isotropic quantum Rabi model. Therefore, we suggest using photon-bunching measurement to characterize the quantum phase transition of qubit-photon hybrid systems.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Physics, Multidisciplinary
You-Fei Xie, Qing-Hu Chen
Summary: In this study, symmetry operators associated with hidden symmetry in the asymmetric Rabi model are derived using the Bogoliubov operator approach, allowing for arbitrary multiples. A general parity operator is also defined, which includes the well-known parity operator.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Multidisciplinary
Marco Cattaneo, Gian Luca Giorgi, Sabrina Maniscalco, Gheorghe Sorin Paraoanu, Roberta Zambrini
Summary: This study investigates the various phenomena that may arise when a pair of qubits are affected by a common environment, and defines time-independent metrics for entanglement generation, quantum synchronization, and subradiance, while analyzing their dependence on model parameters. The results indicate that synchronization and subradiance can serve as reliable signatures of an entangling common-bath, showing the potential applications in a general scenario.
ANNALEN DER PHYSIK
(2021)
Article
Quantum Science & Technology
Sergey Danilin, Joao Barbosa, Michael Farage, Zimo Zhao, Xiaobang Shang, Jonathan Burnett, Nick Ridler, Chong Li, Martin Weides
Summary: This article discusses the importance of electromagnetic filtering for superconducting quantum circuits and proposes methods to reduce noise photon flux through filtered wiring and cryogenic microwave low-pass filters.
EPJ QUANTUM TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
M. R. Perelshtein, A. Pakhomchik, A. A. Melnikov, A. A. Novikov, A. Glatz, G. S. Paraoanu, V. M. Vinokur, G. B. Lesovik
Summary: This study utilizes phase estimation and classical optimization algorithms for solving a specific class of large linear systems of equations. By introducing the entanglement properties of the associated phase estimation operation and a straightforward matrix-to-circuit map, an efficient search for solutions is achieved. A record-breaking result for solving a 2(17)-dimensional linear system is demonstrated on IBM quantum computer processors.
ANNALEN DER PHYSIK
(2022)
Article
Physics, Multidisciplinary
Luigi Giannelli, Pierpaolo Sgroi, Jonathon Brown, Gheorghe Sorin Paraoanu, Mauro Paternostro, Elisabetta Paladino, Giuseppe Falci
Summary: Quantum Optimal Control and Reinforcement Learning are effective methods for solving control problems in quantum systems, which can be implemented using machine learning techniques. This tutorial introduces these methods and provides examples using the problem of three-level population transfer.
Article
Optics
Shruti Dogra, Gheorghe Sorin Paraoanu
Summary: In this study, we achieved perfect population transfer in stimulated Raman adiabatic passage using a well-tailored sequence of two Gaussian-pulsed drives. We analytically examined the optimal truncation and relative placement of the Stokes and pump pulses and determined the power and duration of the protocol for a given pulse width. Notably, we found that the duration of the protocol required to achieve a desired fidelity value logarithmically depends on the infidelity. Furthermore, we introduced a new adiabaticity criteria that is remarkably simple and effective, based on optimal truncation of the drives and reference to the point of fastest transfer.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2022)
Article
Quantum Science & Technology
Iivari Pietikainen, Ondrej Cernotik, Shruti Puri, Radim Filip, S. M. Girvin
Summary: In hybrid circuit quantum electrodynamics, a controlled beam splitter gate is a powerful resource for creating ancilla-controlled SWAP gates, executing swap tests, preparing quantum non-Gaussian entanglement, and measuring nonlinear functionals of quantum states. A new realization of a hybrid cSWAP using "Kerr-cat" qubits offers important benefits for quantum computation.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Physics, Applied
M. R. Perelshtein, K. V. Petrovnin, V. Vesterinen, S. Hamedani Raja, I. Lilja, M. Will, A. Savin, S. Simbierowicz, R. N. Jabdaraghi, J. S. Lehtinen, L. Groenberg, J. Hassel, M. P. Prunnila, J. Govenius, G. S. Paraoanu, P. J. Hakonen
Summary: Entangled microwave photons are a valuable resource for quantum information processing and sensing. In this study, we demonstrate the generation of frequency-entangled photons at a high rate using a low-loss Josephson metamaterial. Additionally, single-mode squeezing is achieved in such devices.
PHYSICAL REVIEW APPLIED
(2022)
Article
Multidisciplinary Sciences
Shruti Dogra, Antti Vepsaelaeinen, Gheorghe Sorin Paraoanu
Summary: In this study, we experimentally and theoretically investigate population transfer between the ground state and the second excited state in a transmon circuit using superadiabatic stimulated Raman adiabatic passage (saSTIRAP). We demonstrate that the transfer is highly robust against variations in pulse amplitudes, showing that the superadiabatic process inherits certain robustness features from the adiabatic one. Additionally, we provide new evidence of a plateau phenomenon that occurs at high values of the counterdiabatic pulse strength, extending the usual framework of saSTIRAP.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Multidisciplinary Sciences
Shruti Dogra, John J. McCord, Gheorghe Sorin Paraoanu
Summary: Researchers propose the concept of coherent interaction-free detection and demonstrate it experimentally using a superconducting transmon circuit. Compared to standard setups, this method employs a fully coherent evolution and achieves a higher probability of success. Experimental results show that it is possible to determine the presence of a microwave pulse resonant with the second transition of the transmon without exciting the device onto the third level.
NATURE COMMUNICATIONS
(2022)
Article
Quantum Science & Technology
R. Di Candia, F. Minganti, K. V. Petrovnin, G. S. Paraoanu, S. Felicetti
Summary: We evaluate the metrological power of parametric Kerr resonators undergoing driven-dissipative phase transitions, and fully characterize the quantum Fisher information for frequency estimation and the Helstrom bound for frequency discrimination. We demonstrate that experimental parameters can achieve Heisenberg precision beyond the asymptotic regime. We propose protocols using the critical behavior of nonlinear resonators to enhance the precision of quantum magnetometers and the fidelity of superconducting qubit readout.
NPJ QUANTUM INFORMATION
(2023)
Article
Optics
N. N. Gusarov, M. R. Perelshtein, P. J. Hakonen, G. S. Paraoanu
Summary: Quantum magnetometry based on adaptive phase estimation achieves Heisenberg precision without the need for complex entangled states. The study addresses limitations in the use of quantum resources and algorithmic realizations, and advances the time-ascending phase estimation protocol through numerical improvements and optimal exploitation of limited coherence in unentangled qubits. Experimental results on the IBMQ platform demonstrate comparable sensitivity to established magnetometry platforms for slowly oscillating magnetic fields in the range of 1-10 kHz.
Article
Physics, Multidisciplinary
John J. McCord, Shruti Dogra, Gheorghe Sorin Paraoanu
Summary: Quantum physics allows for the detection of objects without photon absorption through interaction-free measurements. We present a three-level system formulation where a resonantly coupled pulse serves as the object to be detected. By replacing projection operators with coherent interactions, our protocol achieves higher detection efficiencies than the traditional projective protocol. We demonstrate that our coherent protocol reaches the Heisenberg limit and remains robust under various errors and initial states.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Computer Science, Information Systems
Hany Khalifa, Kirill Petrovnin, Riku Jantti, Gheorghe Sorin Paraoanu
Summary: Quantum illumination utilizes non-classical correlations in CV entangled modes to detect targets in thermal noise, a new QI receiver is proposed using a CV-controlled CNOT for joint measurement, the detection process involves homodyne measurements and square-law detectors. The device can outperform others in certain conditions and achieve optimal performance, and can also be implemented in the optical domain, expanding its applications beyond microwaves.
Article
Quantum Science & Technology
Kirill Viktorovich Petrovnin, Michael Romanovich Perelshtein, Tero Korkalainen, Visa Vesterinen, Ilari Lilja, Gheorghe Sorin Paraoanu, Pertti Juhani Hakonen
Summary: In this work, the generation and control of genuine tripartite and quadripartite quantum entanglement states are achieved by utilizing the phase difference between pump tones. The study provides a comprehensive control toolbox for entanglement structures and enhances the prospects of quantum data processing using parametric microwave cavities.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Review
Quantum Science & Technology
Marco Cattaneo, Gheorghe Sorin Paraoanu
Summary: This article discusses the importance of dissipation engineering in various fields and how to simulate thermal baths in superconducting qubit networks. It also introduces new results in the weak coupling limit, showing that common examples of open quantum systems can be simulated through capacitively coupled superconducting qubits and resistors.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
