Quantum

Paper

Programmable adiabatic demagnetization for systems with trivial and topological excitations

Anne Matthies, Mark Rudner, Achim Rosch, and Erez Berg,

Quantum 8, 1505 (2024).

We propose a simple, robust protocol to prepare a low-energy state of an arbitrary Hamiltonian on a quantum computer or programmable quantum simulator. The protocol is inspired by the adiaba…

Paper

Option pricing under stochastic volatility on a quantum computer

Guoming Wang and Angus Kan,

Quantum 8, 1504 (2024).

We develop quantum algorithms for pricing Asian and barrier options under the Heston model, a popular stochastic volatility model, and estimate their costs, in terms of T-count, T-depth and…

Paper

Random Natural Gradient

Ioannis Kolotouros and Petros Wallden,

Quantum 8, 1503 (2024).

Hybrid quantum-classical algorithms appear to be the most promising approach for near-term quantum applications. An important bottleneck is the classical optimization loop, where the multipl…

Paper

Efficient Parameter Optimisation for Quantum Kernel Alignment: A Sub-sampling Approach in Variational Training

M. Emre Sahin, Benjamin C. B. Symons, Pushpak Pati, Fayyaz Minhas, Declan Millar, Maria Gabrani, Stefano Mensa, and Jan Lukas Robertus,

Quantum 8, 1502 (2024).

Quantum machine learning with quantum kernels for classification problems is a growing area of research. Recently, quantum kernel alignment techniques that parameterise the kernel have been…

Paper

Quantum Locally Testable Code with Constant Soundness

Andrew Cross, Zhiyang He, Anand Natarajan, Mario Szegedy, and Guanyu Zhu,

Quantum 8, 1501 (2024).

In this paper, we present two constructions of quantum locally testable codes (QLTC) with constant soundness. In the first approach, we introduce an operation called check product, and show…

Paper

Resource Efficient Boolean Function Solver on Quantum Computer

Xiang Li, Hanxiang Shen, Weiguo Gao, and Yingzhou Li,

Quantum 8, 1500 (2024).

Nonlinear boolean equation systems play an important role in a wide range of applications. Grover's algorithm is one of the best-known quantum search algorithms in solving the nonlinear bool…

Paper

Quantum teleportation implies symmetry-protected topological order

Yifan Hong, David T. Stephen, and Aaron J. Friedman,

Quantum 8, 1499 (2024).

We constrain a broad class of teleportation protocols using insights from locality. In the “standard'' teleportation protocols we consider, all outcome-dependent unitaries are Pauli operato…

Paper

Decoding algorithms for surface codes

Antonio deMarti iOlius, Patricio Fuentes, Román Orús, Pedro M. Crespo, and Josu Etxezarreta Martinez,

Quantum 8, 1498 (2024).

Quantum technologies have the potential to solve certain computationally hard problems with polynomial or super-polynomial speedups when compared to classical methods. Unfortunately, the uns…

Paper

Quantum lozenge tiling and entanglement phase transition

Zhao Zhang and Israel Klich,

Quantum 8, 1497 (2024).

While volume violation of area law has been exhibited in several quantum spin chains, the construction of a corresponding ground state in higher dimensions, entangled in more than one direct…

Paper

Implementing any Linear Combination of Unitaries on Intermediate-term Quantum Computers

Shantanav Chakraborty,

Quantum 8, 1496 (2024).

We develop three new methods to implement any Linear Combination of Unitaries (LCU), a powerful quantum algorithmic tool with diverse applications. While the standard LCU procedure requires…

Paper

Iteration Complexity of Variational Quantum Algorithms

Vyacheslav Kungurtsev, Georgios Korpas, Jakub Marecek, and Elton Yechao Zhu,

Quantum 8, 1495 (2024).

There has been much recent interest in near-term applications of quantum computers, i.e., using quantum circuits that have short decoherence times due to hardware limitations. Variational qu…

Paper

Branching States as The Emergent Structure of a Quantum Universe

Akram Touil, Fabio Anza, Sebastian Deffner, and James P. Crutchfield,

Quantum 8, 1494 (2024).

Quantum Darwinism builds on decoherence theory to explain the emergence of classical behavior in a fundamentally quantum universe. Within this framework we prove two crucial insights about t…

Paper

Quantum-classical tradeoffs and multi-controlled quantum gate decompositions in variational algorithms

Teague Tomesh, Nicholas Allen, Daniel Dilley, and Zain Saleem,

Quantum 8, 1493 (2024).

The computational capabilities of near-term quantum computers are limited by the noisy execution of gate operations and a limited number of physical qubits. Hybrid variational algorithms are…

Paper

Mixed-state additivity properties of magic monotones based on quantum relative entropies for single-qubit states and beyond

Roberto Rubboli, Ryuji Takagi, and Marco Tomamichel,

Quantum 8, 1492 (2024).

We prove that the stabilizer fidelity is multiplicative for the tensor product of an arbitrary number of single-qubit states. We also show that the relative entropy of magic becomes additive…

Paper

Differentiating and Integrating ZX Diagrams with Applications to Quantum Machine Learning

Quanlong Wang, Richie Yeung, and Mark Koch,

Quantum 8, 1491 (2024).

ZX-calculus has proved to be a useful tool for quantum technology with a wide range of successful applications. Most of these applications are of an algebraic nature. However, other tasks th…

Paper

Repeated measurements on non-replicable systems and their consequences for Unruh-DeWitt detectors

Nicola Pranzini, Guillermo García-Pérez, Esko Keski-Vakkuri, and Sabrina Maniscalco,

Quantum 8, 1490 (2024).

The Born rule describes the probability of obtaining an outcome when measuring an observable of a quantum system. As it can only be tested by measuring many copies of the system under consid…

Category: Paper