252 citations · 1.1k across the 16 of their papers we have counts for
16 papers
Measuring the quantum state of photoelectrons
Hugo Laurell, Sizuo Luo, Robin Weissenbilder +17
A photoelectron, emitted due to the absorption of light quanta as described by the photoelectric effect, is often characterized experimentally by a classical quantity, its momentum…
Quantum process tomography of continuous-variable gates using coherent states
Mikael Kervinen, Shahnawaz Ahmed, Marina Kudra +5
Encoding quantum information into superpositions of multiple Fock states of a harmonic oscillator can provide protection against errors, but it comes with the cost of requiring mor…
Implicit differentiation of variational quantum algorithms
Shahnawaz Ahmed, Nathan Killoran, Juan Felipe Carrasquilla Álvarez
Several quantities important in condensed matter physics, quantum information, and quantum chemistry, as well as quantities required in meta-optimization of machine learning algori…
Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
Liangyu Chen, Hang-Xi Li, Yong Lu +17
High-fidelity and rapid readout of a qubit state is key to quantum computing and communication, and it is a prerequisite for quantum error correction. We present a readout scheme f…
Gradient-descent quantum process tomography by learning Kraus operators
Shahnawaz Ahmed, Fernando Quijandría, Anton Frisk Kockum
We perform quantum process tomography (QPT) for both discrete- and continuous-variable quantum systems by learning a process representation using Kraus operators. The Kraus form en…
Extensive characterization of a family of efficient three-qubit gates at the coherence limit
Christopher W. Warren, Jorge Fernández-Pendás, Shahnawaz Ahmed +13
While all quantum algorithms can be expressed in terms of single-qubit and two-qubit gates, more expressive gate sets can help reduce the algorithmic depth. This is important in th…
Diagnosing quantum chaos with out-of-time-ordered-correlator quasiprobability in the kicked-top model
José Raúl González Alonso, Nathan Shammah, Shahnawaz Ahmed +2
While classical chaos has been successfully characterized with consistent theories and intuitive techniques, such as with the use of Lyapunov exponents, quantum chaos is still poor…
Robust preparation of Wigner-negative states with optimized SNAP-displacement sequences
Marina Kudra, Mikael Kervinen, Ingrid Strandberg +13
Hosting non-classical states of light in three-dimensional microwave cavities has emerged as a promising paradigm for continuous-variable quantum information processing. Here we ex…
Pulse-level noisy quantum circuits with QuTiP
Boxi Li, Shahnawaz Ahmed, Sidhant Saraogi +4
The study of the impact of noise on quantum circuits is especially relevant to guide the progress of Noisy Intermediate-Scale Quantum (NISQ) computing. In this paper, we address th…
Classification and reconstruction of optical quantum states with deep neural networks
Shahnawaz Ahmed, Carlos Sánchez Muñoz, Franco Nori +1
We apply deep-neural-network-based techniques to quantum state classification and reconstruction. We demonstrate high classification accuracies and reconstruction fidelities, even…
QuTiP-BoFiN: A bosonic and fermionic numerical hierarchical-equations-of-motion library with applications in light-harvesting, quantum control, and single-molecule electronics
Neill Lambert, Tarun Raheja, Simon Cross +5
The "hierarchical equations of motion" (HEOM) method is a powerful exact numerical approach to solve the dynamics and find the steady-state of a quantum system coupled to a non-Mar…
Quantum State Tomography with Conditional Generative Adversarial Networks
Shahnawaz Ahmed, Carlos Sánchez Muñoz, Franco Nori +1
Quantum state tomography (QST) is a challenging task in intermediate-scale quantum devices. Here, we apply conditional generative adversarial networks (CGANs) to QST. In the CGAN f…
Fitting IVIM with Variable Projection and Simplicial Optimization
Shreyas Fadnavis, Hamza Farooq, Maryam Afzali +10
Fitting multi-exponential models to Diffusion MRI (dMRI) data has always been challenging due to various underlying complexities. In this work, we introduce a novel and robust fitt…
Virtual excitations in the ultra-strongly-coupled spin-boson model: physical results from unphysical modes
Neill Lambert, Shahnawaz Ahmed, Mauro Cirio +1
Here we show how, in the ultra-strongly-coupled spin-boson model, apparently unphysical "Matsubara modes" are required not only to regulate detailed balance, but also to arrive at…
PennyLane: Automatic differentiation of hybrid quantum-classical computations
Ville Bergholm, Josh Izaac, Maria Schuld +65
PennyLane is a Python 3 software framework for differentiable programming of quantum computers. The library provides a unified architecture for near-term quantum computing devices,…
Open quantum systems with local and collective incoherent processes: Efficient numerical simulation using permutational invariance
Nathan Shammah, Shahnawaz Ahmed, Neill Lambert +2
The permutational invariance of identical two-level systems allows for an exponential reduction in the computational resources required to study the Lindblad dynamics of coupled sp…