English
Related papers

Related papers: A Method of Determining Excited-States for Quantum…

200 papers

Determining quantum excited states is crucial across physics and chemistry but presents significant challenges for variational methods, primarily due to the need to enforce orthogonality to lower-energy states, often requiring…

Quantum Physics · Physics 2025-05-01 Shi-Xin Zhang , Lei Wang

The efficient calculation of Hamiltonian spectra, a problem often intractable on classical machines, can find application in many fields, from physics to chemistry. Here, we introduce the concept of an "eigenstate witness" and through it…

Processes related to electronically excited states are central in many areas of science, however accurately determining excited-state energies remains a major challenge in theoretical chemistry. Recently, higher energy stationary states of…

Chemical Physics · Physics 2020-06-05 Hugh G. A. Burton , Alex J. W. Thom , Pierre-François Loos

We propose quantum-selected configuration interaction (QSCI), a class of hybrid quantum-classical algorithms for calculating the ground- and excited-state energies of many-electron Hamiltonians on noisy quantum devices. Suppose that an…

Quantum Physics · Physics 2023-02-23 Keita Kanno , Masaya Kohda , Ryosuke Imai , Sho Koh , Kosuke Mitarai , Wataru Mizukami , Yuya O. Nakagawa

Solving for molecular excited states remains one of the key challenges of modern quantum chemistry. Traditional methods are constrained by existing computational capabilities, limiting the complexity of the molecules that can be studied or…

Quantum Physics · Physics 2021-04-13 Jules Tilly , Glenn Jones , Hongxiang Chen , Leonard Wossnig , Edward Grant

Recently, it has been shown that the ground-state energy of a quantum many-body system can be written in terms of cumulants. In this paper we show that the energies of excited states can be expressed similarly. These representations are…

Condensed Matter · Physics 2007-05-23 T. Schork , P. Fulde

We present a quantum-classical hybrid random power method that approximates a ground state of a Hamiltonian. The quantum part of our method computes a fixed number of elements of a Hamiltonian-matrix polynomial via quantum polynomial…

Quantum Physics · Physics 2025-04-17 Taehee Ko , Hyowon Park , Sangkook Choi

The Hubbard model is a challenging quantum many-body problem and serves as a benchmark for quantum computing research. Accurate computation of its ground and excited state energies is essential for understanding correlated electron systems.…

Quantum Physics · Physics 2025-09-03 Mrinal Dev , Bikash K. Behera , Vivek Vyas , Prasanta K. Panigrahi

The task of estimating the ground state of Hamiltonians is an important problem in physics with numerous applications ranging from solid-state physics to combinatorial optimization. We provide a hybrid quantum-classical algorithm for…

Quantum Physics · Physics 2022-02-28 Kishor Bharti , Tobias Haug

Highly excited vibrational states of an isolated molecule encode the vibrational energy flow pathways in the molecule. Recent studies have had spectacular success in understanding the nature of the excited states mainly due to the extensive…

Chemical Physics · Physics 2009-11-07 A. Semparithi , V. Charulatha , S. Keshavamurthy

Quantum chemistry is one of the important applications of quantum information technology. Especially, an estimation of the energy gap between a ground state and excited state of a target Hamiltonian corresponding to a molecule is essential.…

Quantum Physics · Physics 2020-07-22 Yuichiro Matsuzaki , Hideaki Hakoshima , Kenji Sugisaki , Yuya Seki , Shiro Kawabata

Understanding the properties of excited states of complex molecules is crucial for many chemical and physical processes. Calculating these properties is often significantly more resource-intensive than calculating their ground state…

Quantum Physics · Physics 2025-05-08 Manuel Hagelüken , Marco F. Huber , Marco Roth

We present a study of the two dimensional circular quantum dot model Hamiltonian using a range of quantum chemical ab initio methods. Ground and excited state energies are computed on different levels of perturbation theories including the…

Chemical Physics · Physics 2022-03-23 Faruk Salihbegović , Alejandro Gallo , Andreas Grüneis

We propose an excited-state molecular dynamics simulation method based on variational quantum algorithms at a computational cost comparable to that of ground-state simulations. We utilize the feature that excited states can be obtained as…

Chemical Physics · Physics 2023-03-02 Hirotoshi Hirai

The ability of near-term quantum computers to represent classically-intractable quantum states has brought much interest in using such devices for estimating the ground and excited state energies of fermionic Hamiltonians. The usefulness of…

Quantum Physics · Physics 2021-06-10 Maxwell D. Radin , Peter Johnson

Calculating the molecular ground-state energy is a central challenge in computational chemistry. Conventional methods such as the Complete Active Space Configuration Interaction scale exponentially with molecular size, limiting their…

Quantum Physics · Physics 2025-12-15 Stefano Bruni , Enrico Prati

A systematic method to calculate the low energy spectrum of SU(2) Yang-Mills quantum mechanics with high precision is given and applied to obtain the energies of the groundstate and the first few excited states.

High Energy Physics - Theory · Physics 2009-10-31 A. M. Khvedelidze , H. -P. Pavel

Traditional quantum physics solves ground states for a given Hamiltonian, while quantum information science asks for the existence and construction of certain Hamiltonians for given ground states. In practical situations, one would be…

Quantum Physics · Physics 2013-05-30 Jianxin Chen , Zhengfeng Ji , Bei Zeng , D. L. Zhou

NISQ era devices suffer from a number of challenges like limited qubit connectivity, short coherence times and sizable gate error rates. Thus, quantum algorithms are desired that require shallow circuit depths and low qubit counts to take…

Estimating the ground-state energy of Hamiltonians is a fundamental task for which it is believed that quantum computers can be helpful. Several approaches have been proposed toward this goal, including algorithms based on quantum phase…

Quantum Physics · Physics 2025-11-26 Dhrumil Patel , Daniel Koch , Saahil Patel , Mark M. Wilde