1.6k citations · 7k across the 88 of their papers we have counts for
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Entangling Power and Symmetries in the Quantum Rabi Model
Ian Low, Jens Koch, Sahel Ashhab
The quantum Rabi model is a standard effective Hamiltonian in studies of light-matter interaction, capturing the simplest nontrivial setting in which a qubit couples to a single ha…
Is the most random pattern random? Maximizing localization in a two-dimensional lattice with engineered disorder
Morgan Berkane, Sahel Ashhab
We investigate localization in two models: a single particle in a two-dimensional square lattice described by the tight binding Hamiltonian, and a two-dimensional square qubit latt…
Computational and physical complexity of synthesizing random multi-qudit quantum states and unitary operators
Sahel Ashhab, Bora Basyildiz
We analyze the complexity of synthesizing random states and unitary operators in a multi-qudit system in two paradigms. In one case, we consider the situation in which we manipulat…
Reinforcement Learning for Robust Calibration of Multi-Qudit Quantum Gates
Amine Jaouadi, Sahel Ashhab
Higher-dimensional quantum systems, such as qudits, offer architectural and algorithmic advantages over qubits, but their increased spectral crowding and limited controllability re…
Digital Quantum Simulation of the Holstein-Primakoff Transformation on Noisy Qubits
Kelvin Yip, Alessandro Monteros, Sahel Ashhab +1
Quantum simulation of many-body systems offers a powerful approach to exploring collective quantum dynamics beyond classical computational reach. Although spin and fermionic models…
Reply to Comment on "Properties and dynamics of generalized squeezed states"
Sahel Ashhab, Mohammad Ayyash
In our paper [1], our numerical simulations showed that, unlike displacement and conventional squeezing, higher-order squeezing exhibits oscillatory dynamics. Subsequently, Gordill…
Fractional squeezing: spectra and dynamics from generalized squeezing Hamiltonian with fractional orders
Sahel Ashhab
We generalize the generalized-squeezing problem to include fractional values of the squeezing order . This approach allows us to determine the locations of critical points at wh…
Speed limits of two-qutrit gates
Bora Basyildiz, Zhexuan Gong, Sahel Ashhab
The speed of elementary quantum gates sets a limit on the speed at which quantum circuits can be applied and, as a result, the size of the computations that can be performed on a q…
Fast Bosonic Control via Multiphoton Qubit-Oscillator Interactions
Noah Gorgichuk, Mohammad Ayyash, Matteo Mariantoni +1
We study the problem of -fold rotationally symmetric bosonic state preparation, which is of great importance to bosonic quantum error correction, using a multiphoton interaction…
Statistical analysis of barren plateaus in variational quantum algorithms
Le Bin Ho, Jesus Urbaneja, Sahel Ashhab
We investigate the barren plateau (BP) phenomenon in variational quantum algorithms using a statistical approach. Using Gaussian function models, we identify three distinct types o…
Finite-dimensional approximations of generalized squeezing
Sahel Ashhab, Felix Fischer, Davide Lonigro +2
We show unexpected behaviour in simulations of generalized squeezing performed with finite-dimensional truncations of the Fock space: even for extremely large dimension of the stat…
Physically motivated decompositions of single-qutrit gates
Aryan Iliat, Mark Byrd, Sahel Ashhab +1
Although only two quantum states of a physical system are often used to encode quantum information in the form of qubits, many levels can in principle be used to obtain qudits and…
Automated discovery and optimization of autonomous quantum error correction codes for a general open quantum system
Sahel Ashhab
We develop a method to search for the optimal code space, induced decay rates and control Hamiltonian to implement autonomous quantum error correction (AQEC) for a general open qua…
Dispersive regime of multiphoton qubit-oscillator interactions
Mohammad Ayyash, Sahel Ashhab
The dispersive regime of -photon qubit-oscillator interactions is analyzed using Schrieffer-Wolff perturbation theory. Effective Hamiltonians are derived up to the second order…
Properties and dynamics of generalized squeezed states
Sahel Ashhab, Mohammad Ayyash
We analyze the properties and dynamics of generalized squeezed states. We find that, in stark contrast to displacement and two-photon squeezing, higher-order squeezing leads to osc…
Driven Multiphoton Qubit-Resonator Interactions
Mohammad Ayyash, Xicheng Xu, Sahel Ashhab +1
We develop a general theory for multiphoton qubit-resonator interactions enhanced by a qubit drive. The interactions generate qubit-conditional operations in the resonator when the…
Quantum circuit synthesis via a random combinatorial search
Sahel Ashhab, Fumiki Yoshihara, Miwako Tsuji +2
We use a random search technique to find quantum gate sequences that implement perfect quantum state preparation or unitary operator synthesis with arbitrary targets. This approach…
High-frequency suppression of inductive coupling between flux qubit and transmission line resonator
Sahel Ashhab, Ziqiao Ao, Fumiki Yoshihara +2
We perform theoretical calculations to investigate the naturally occurring high-frequency cutoff in a circuit comprising a flux qubit coupled inductively to a transmission line res…
Controlling qubit-oscillator systems using linear parameter sweeps
Sahel Ashhab, Tomoko Fuse, Fumiki Yoshihara +2
We investigate the dynamics of a qubit-oscillator system under the influence of a linear sweep of system parameters. We consider two main cases. In the first case, we consider swee…
Extremely large Lamb shift in a deep-strongly coupled circuit QED system with a multimode resonator
Ziqiao Ao, Sahel Ashhab, Fumiki Yoshihara +5
We report experimental and theoretical results on the extremely large Lamb shift in a multimode circuit quantum electrodynamics (QED) system in the deep-strong coupling (DSC) regim…
Numerical analysis of quantum circuits for state preparation and unitary operator synthesis
Sahel Ashhab, Naoki Yamamoto, Fumiki Yoshihara +1
We perform optimal-control-theory calculations to determine the minimum number of two-qubit CNOT gates needed to perform quantum state preparation and unitary operator synthesis fo…
Speed limits for two-qubit gates with weakly anharmonic qubits
Sahel Ashhab, Fumiki Yoshihara, Tomoko Fuse +3
We consider the implementation of two-qubit gates when the physical systems used to realize the qubits possess additional quantum states in the accessible energy range. We use opti…
Enhanced coherence of all-nitride superconducting qubits epitaxially grown on silicon substrate
Sunmi Kim, Hirotaka Terai, Taro Yamashita +6
Improving the coherence of superconducting qubits is a fundamental step towards the realization of fault-tolerant quantum computation. However, coherence times of quantum circuits…
Characterization of Control in a Superconducting Qutrit Using Randomized Benchmarking
M. Kononenko, M. A. Yurtalan, S. Ren +3
We characterize control of a qutrit implemented in the lowest three energy levels of a capacitively-shunted flux-biased superconducting circuit. Randomized benchmarking over the qu…