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View article: Advances in Quantum Computation in NISQ Era
Advances in Quantum Computation in NISQ Era Open
Realizing a universal, fault-tolerant quantum computer remains challenging with current technology [...]
View article: TE-PAI: exact time evolution by sampling random circuits
TE-PAI: exact time evolution by sampling random circuits Open
Simulating time evolution under quantum Hamiltonians is one of the most natural applications of quantum computers. We introduce TE-PAI, which simulates time evolution exactly by sampling random quantum circuits for the purpose of estimatin…
View article: Space-time trade-off in networked virtual distillation
Space-time trade-off in networked virtual distillation Open
In contrast to monolithic devices, modular, networked quantum architectures are based on interconnecting smaller quantum hardware nodes using quantum communication links and offer a promising approach to scalability. Virtual distillation (…
View article: Space and Time Cost of Continuous Rotations in Surface Codes
Space and Time Cost of Continuous Rotations in Surface Codes Open
While Clifford operations are relatively easy to implement in fault-tolerant quantum computers,continuous rotation gates remain a significant bottleneck in typical quantum algorithms. In this work, we ask the question: "What is the most ef…
View article: Erratum: Low-depth phase oracle using a parallel piecewise circuit [Phys. Rev. A <b>111</b>, 062420 (2025)]
Erratum: Low-depth phase oracle using a parallel piecewise circuit [Phys. Rev. A <b>111</b>, 062420 (2025)] Open
View article: Exponential distillation of dominant eigenproperties
Exponential distillation of dominant eigenproperties Open
Estimating observable expectation values in eigenstates of quantum systems has a broad range of applications and is an area where early fault-tolerant quantum computers may provide practical quantum advantage. We develop a hybrid quantum-c…
View article: Biased estimator channels for classical shadows
Biased estimator channels for classical shadows Open
Extracting classical information from quantum systems is of fundamental importance, and classical shadows allow us to extract a large amount of information using relatively few measurements. Conventional shadow estimators are unbiased and …
View article: Algorithmic Shadow Spectroscopy
Algorithmic Shadow Spectroscopy Open
We present shadow spectroscopy as a simulator-agnostic quantum algorithm for estimating energy gaps using very few circuit repetitions (shots) and no extra resources (ancilla qubits) beyond performing time evolution and measurements. The a…
View article: Preparing ground and excited states using adiabatic CoVaR
Preparing ground and excited states using adiabatic CoVaR Open
CoVariance Root finding with classical shadows (CoVaR) was recently introduced as a new paradigm for training variational quantum circuits. Common approaches, such as variants of the variational quantum eigensolver, aim to optimise a non-l…
View article: Myths around quantum computation before full fault tolerance: What no-go theorems rule out and what they don't
Myths around quantum computation before full fault tolerance: What no-go theorems rule out and what they don't Open
In this perspective article, we revisit and critically evaluate prevailing viewpoints on the capabilities and limitations of near-term quantum computing and its potential transition toward fully fault-tolerant quantum computing. We examine…
View article: Snakes on a Plane: mobile, low dimensional logical qubits on a 2D surface
Snakes on a Plane: mobile, low dimensional logical qubits on a 2D surface Open
Recent demonstrations indicate that silicon-spin QPUs will be able to shuttle physical qubits rapidly and with high fidelity - a desirable feature for maximising logical connectivity, supporting new codes, and routing around damage. Howeve…
View article: Quantum Information Processing, Sensing, and Communications: Their Myths, Realities, and Futures
Quantum Information Processing, Sensing, and Communications: Their Myths, Realities, and Futures Open
The recent advances in quantum information processing, sensing and\ncommunications are surveyed with the objective of identifying the associated\nknowledge gaps and formulating a roadmap for their future evolution. Since the\noperation of …
View article: Sparse Probabilistic Synthesis of Quantum Operations
Sparse Probabilistic Synthesis of Quantum Operations Open
Successful implementations of quantum technologies require protocols and algorithms that use as few quantum resources as possible. However, many important quantum operations, such as continuous rotation gates in quantum computing or broadb…
View article: TE-PAI: Exact Time Evolution by Sampling Random Circuits
TE-PAI: Exact Time Evolution by Sampling Random Circuits Open
Simulating time evolution under quantum Hamiltonians is one of the most natural applications of quantum computers. We introduce TE-PAI, which simulates time evolution exactly by sampling random quantum circuits for the purpose of estimatin…
View article: Preparing Ground and Excited States Using Adiabatic CoVaR
Preparing Ground and Excited States Using Adiabatic CoVaR Open
CoVarince Root finding with classical shadows (CoVaR) was recently introduced as a new paradigm for training variational quantum circuits. Common approaches, such as variants of the Variational Quantum Eigensolver, aim to optimise a non-li…
View article: Low Depth Phase Oracle Using a Parallel Piecewise Circuit
Low Depth Phase Oracle Using a Parallel Piecewise Circuit Open
We explore the important task of applying a phase $\exp(i\,f(x))$ to a computational basis state $\left| x \right>$. The closely related task of rotating a target qubit by an angle depending on $f(x)$ is also studied. Such operations are k…
View article: Purification and correction of quantum channels by commutation-derived quantum filters
Purification and correction of quantum channels by commutation-derived quantum filters Open
Reducing errors is essential for reliable quantum computation. Quantum error mitigation (QEM) and quantum error correction (QEC) are two leading approaches for this task, each with challenges: QEM suffers from high sampling costs and canno…
View article: Probabilistic Interpolation of Quantum Rotation Angles
Probabilistic Interpolation of Quantum Rotation Angles Open
Quantum computing requires a universal set of gate operations; regarding gates as rotations, any rotation angle must be possible. However a real device may only be capable of B bits of resolution, i.e., it might support only 2B possible va…
View article: Sparse Probabilistic Synthesis of Quantum Operations
Sparse Probabilistic Synthesis of Quantum Operations Open
Successful implementations of quantum technologies require protocols and algorithms that use as few quantum resources as possible. However, many important quantum operations, such as continuous rotation gates in quantum computing or broadb…
View article: Biased Estimator Channels for Classical Shadows
Biased Estimator Channels for Classical Shadows Open
Extracting classical information from quantum systems is of fundamental importance, and classical shadows allow us to extract a large amount of information using relatively few measurements. Conventional shadow estimators are unbiased and …
View article: Quantum Error Mitigated Classical Shadows
Quantum Error Mitigated Classical Shadows Open
Classical shadows enable us to learn many properties of a quantum state ρ with very few measurements. However, near-term and early fault-tolerant quantum computers will only be able to prepare noisy quantum states ρ and it is thus a consid…
View article: Can shallow quantum circuits scramble local noise into global white noise?
Can shallow quantum circuits scramble local noise into global white noise? Open
Shallow quantum circuits are believed to be the most promising candidates for achieving early practical quantum advantage—this has motivated the development of a broad range of error mitigation techniques whose performance generally improv…
View article: Distributed Simulation of Statevectors and Density Matrices
Distributed Simulation of Statevectors and Density Matrices Open
Classical simulation of quantum computers is an irreplaceable step in the design of quantum algorithms. Exponential simulation costs demand the use of high-performance computing techniques, and in particular distribution, whereby the quant…
View article: Phase Spaces, Parity Operators, and the Born–Jordan Distribution
Phase Spaces, Parity Operators, and the Born–Jordan Distribution Open
Phase spaces as given by the Wigner distribution function provide a natural description of infinite-dimensional quantum systems. They are an important tool in quantum optics and have been widely applied in the context of time–frequency ana…
View article: Probabilistic Interpolation of Quantum Rotation Angles
Probabilistic Interpolation of Quantum Rotation Angles Open
Quantum computing requires a universal set of gate operations; regarding gates as rotations, any rotation angle must be possible. However a real device may only be capable of $B$ bits of resolution, i.e. it might support only $2^B$ possibl…
View article: Quantum Error Mitigated Classical Shadows
Quantum Error Mitigated Classical Shadows Open
Classical shadows enable us to learn many properties of a quantum state $ρ$ with very few measurements. However, near-term and early fault-tolerant quantum computers will only be able to prepare noisy quantum states $ρ$ and it is thus a co…
View article: Can shallow quantum circuits scramble local noise into global white noise?
Can shallow quantum circuits scramble local noise into global white noise? Open
Shallow quantum circuits are believed to be the most promising candidates for achieving early practical quantum advantage - this has motivated the development of a broad range of error mitigation techniques whose performance generally impr…
View article: Algorithmic Shadow Spectroscopy
Algorithmic Shadow Spectroscopy Open
We present shadow spectroscopy as a simulator-agnostic quantum algorithm for estimating energy gaps using very few circuit repetitions (shots) and no extra resources (ancilla qubits) beyond performing time evolution and measurements. The a…
View article: Quantum natural gradient generalized to noisy and nonunitary circuits
Quantum natural gradient generalized to noisy and nonunitary circuits Open
Variational quantum algorithms are promising tools whose efficacy depends on their optimization method. For noise-free unitary circuits, the quantum generalization of natural gradient descent has been introduced and shown to be equivalent …
View article: Training Variational Quantum Circuits with CoVaR: Covariance Root Finding with Classical Shadows
Training Variational Quantum Circuits with CoVaR: Covariance Root Finding with Classical Shadows Open
Exploiting near-term quantum computers and achieving practical value is a considerable and exciting challenge. Most prominent candidates as variational algorithms typically aim to find the ground state of a Hamiltonian by minimizing a sing…