Ruiz Guzman, Edgar Andres Lacroix, Denis

We present a new method to perform variation after projection in many-body systems on quantum computers that does not require performing explicit projection. The technique employs the notion of ``oracle'', generally used in quantum search algorithms. We show how to construct the oracle and the projector associated with a symmetry operator. The proc...

Surov, Ilya A.
Published in
Frontiers in Psychology

Psychology suffers from the absence of mathematically-formalized primitives. As a result, conceptual and quantitative studies lack an ontological basis that would situate them in the company of natural sciences. The article addresses this problem by describing a minimal psychic structure, expressed in the algebra of quantum theory. The structure is...

Krutyanskiy, V. Galli, M. Krcmarsky, V. Baier, S. Fioretto, D.A. Pu, Y. Mazloom, A. Sekatski, P. Canteri, M. Teller, M.
...

We report on an elementary quantum network of two atomic ions separated by 230 m. The ions are trapped in different buildings and connected with 520(2) m of optical fiber. At each network node, the electronic state of an ion is entangled with the polarization state of a single cavity photon; subsequent to interference of the photons at a beamsplitt...

Verdeil, François Deville, Yannick

Quantum state tomography (QST) aims at estimating a quantum state from averaged quantum measurements made on copies of the state. Most quantum algorithms rely on QST at some point and it is a well explored topic in the literature, mostly for mixed states. In this paper we focus on the QST of a pure quantum state using parallel unentangled measureme...

Nadlinger, D. P. Drmota, P. Nichol, B. C. Araneda, G. Main, D. Srinivas, R. Lucas, D. M. Ballance, C. J. Ivanov, K. Tan, E. Y-Z.
...

Cryptographic key exchange protocols traditionally rely on computational conjectures such as the hardness of prime factorisation to provide security against eavesdropping attacks. Remarkably, quantum key distribution protocols like the one proposed by Bennett and Brassard provide information-theoretic security against such attacks, a much stronger ...

Chen, Qianfan Martin, Ivar Jiang, Liang Jin, Dafei
Published in
Quantum Science & Technology

A single electron floating on the surface of a condensed noble-gas liquid or solid can act as a spin qubit with ultralong coherence time, thanks to the extraordinary purity of such systems. Previous studies suggest that the electron spin coherence time on a superfluid helium (He) surface can exceed 100 s. In this paper, we present theoretical studi...

Hlatshwayo, Manqoba Q. Zhang, Yinu Wibowo, Herlik LaRose, Ryan Lacroix, Denis Litvinova, Elena

We simulate the excited states of the Lipkin model using the recently proposed Quantum Equation of Motion (qEOM) method. The qEOM generalizes the EOM on classical computers and gives access to collective excitations based on quasi-boson operators $\hat{O}^\dagger_n(\alpha)$ of increasing configuration complexity $\alpha$. We show, in particular, th...

Edlbauer, Hermann Wang, Junliang Crozes, Thierry Perrier, Pierre Ouacel, Seddik Geffroy, Clément Georgiou, Giorgos Chatzikyriakou, Eleni Lacerda-Santos, Antonio Waintal, Xavier
...

The progress of charge manipulation in semiconductor-based nanoscale devices opened up a novel route to realise a flying qubit with a single electron. In the present review, we introduce the concept of these electron flying qubits, discuss their most promising realisations and show how numerical simulations are applicable to accelerate experimental...

Oliveira, Murilo H. Higgins, Gerard Zhang, Chi Predojević, Ana Hennrich, Markus Bachelard, Romain Villas-Boas, Celso J.

We propose a scheme to dissipatively produce steady-state entanglement in a two-qubit system, via an interaction with a bosonic mode. The system is driven into a stationary entangled state, while we compensate the mode dissipation by injecting energy via a coherent pump field. We also present a scheme which allows us to adiabatically transfer all t...

Madden, Liam Simonetto, Andrea

We study the problem of finding the best approximate circuit that is the closest (in some pertinent metric) to a target circuit, and which satisfies a number of hardware constraints, like gate alphabet and connectivity. We look at the problem in the CNOT+rotation gate set from a mathematical programming standpoint, offering contributions both in te...