Emergence of nematic paramagnet via quantum order-by-disorder and pseudo-Goldstone modes in Kitaev magnets

Matthias Gohlke; Li Ern Chern; Hae-Young Kee; Yong Baek Kim

doi:10.1103/physrevresearch.2.043023

Emergence of nematic paramagnet via quantum order-by-disorder and pseudo-Goldstone modes in Kitaev magnets

Physical Review Research ◽

10.1103/physrevresearch.2.043023 ◽

2020 ◽

Vol 2 (4) ◽

Cited By ~ 1

Author(s):

Matthias Gohlke ◽

Li Ern Chern ◽

Hae-Young Kee ◽

Yong Baek Kim

Keyword(s):

Goldstone Modes ◽

Quantum Order

Download Full-text

Effective Lagrangian for Nambu-Goldstone modes in nonequilibrium open systems

Physical Review D ◽

10.1103/physrevd.103.056020 ◽

2021 ◽

Vol 103 (5) ◽

Author(s):

Masaru Hongo ◽

Suro Kim ◽

Toshifumi Noumi ◽

Atsuhisa Ota

Keyword(s):

Open Systems ◽

Effective Lagrangian ◽

Goldstone Modes

Download Full-text

Asymptotic symmetries and celestial CFT

Journal of High Energy Physics ◽

10.1007/jhep09(2020)176 ◽

2020 ◽

Vol 2020 (9) ◽

Cited By ~ 2

Author(s):

Laura Donnay ◽

Sabrina Pasterski ◽

Andrea Puhm

Keyword(s):

Principal Series ◽

Finite Energy ◽

Continuous Series ◽

Asymptotic Symmetry ◽

Null Infinity ◽

Conformal Dimension ◽

Contour Integrals ◽

Celestial Sphere ◽

Goldstone Modes ◽

Asymptotic Symmetries

Abstract We provide a unified treatment of conformally soft Goldstone modes which arise when spin-one or spin-two conformal primary wavefunctions become pure gauge for certain integer values of the conformal dimension ∆. This effort lands us at the crossroads of two ongoing debates about what the appropriate conformal basis for celestial CFT is and what the asymptotic symmetry group of Einstein gravity at null infinity should be. Finite energy wavefunctions are captured by the principal continuous series ∆ ∈ 1 + iℝ and form a complete basis. We show that conformal primaries with analytically continued conformal dimension can be understood as certain contour integrals on the principal series. This clarifies how conformally soft Goldstone modes fit in but do not augment this basis. Conformally soft gravitons of dimension two and zero which are related by a shadow transform are shown to generate superrotations and non-meromorphic diffeomorphisms of the celestial sphere which we refer to as shadow superrotations. This dovetails the Virasoro and Diff(S2) asymptotic symmetry proposals and puts on equal footing the discussion of their associated soft charges, which correspond to the stress tensor and its shadow in the two-dimensional celestial CFT.

Download Full-text

Demonstration of Shor’s factoring algorithm for N $$=$$ 21 on IBM quantum processors

Scientific Reports ◽

10.1038/s41598-021-95973-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Unathi Skosana ◽

Mark Tame

Keyword(s):

Necessary Condition ◽

Phase Estimation ◽

Proof Of Concept ◽

Residual Phase ◽

Shor's Algorithm ◽

Functional Correctness ◽

Toffoli Gates ◽

Previous Demonstration ◽

Quantum Order ◽

Factoring Algorithm

AbstractWe report a proof-of-concept demonstration of a quantum order-finding algorithm for factoring the integer 21. Our demonstration involves the use of a compiled version of the quantum phase estimation routine, and builds upon a previous demonstration. We go beyond this work by using a configuration of approximate Toffoli gates with residual phase shifts, which preserves the functional correctness and allows us to achieve a complete factoring of $$N=21$$ N = 21 . We implemented the algorithm on IBM quantum processors using only five qubits and successfully verified the presence of entanglement between the control and work register qubits, which is a necessary condition for the algorithm’s speedup in general. The techniques we employ may be useful in carrying out Shor’s algorithm for larger integers, or other algorithms in systems with a limited number of noisy qubits.

Download Full-text