Related papers: Half-Quantum Vortices in Nematic and Chiral Phases…
The half quantum vortex(HQV) in condensate has been studied, since it was predicted by Salomaa and Volovik in superfluid $^3$He-A phase. However, an experimental evidence for its existence has not been reported so far. Motivated by a recent…
Recent experiments on superfluid $^3$He in globally anisotropic aerogels have shown realization of the polar superfluid phase and of the half-quantum vortices (HQVs) in this phase upon rotation. To clarify why the HQVs, which had not been…
Symmetries of the physical world have guided formulation of fundamental laws, including relativistic quantum field theory and understanding of possible states of matter. Topological defects (TDs) often control the universal behavior of…
Stability of a half-quantum vortex (HQV) in superfluid $^3$He has been discussed recently by Kawakami, Tsutsumi and Machida in Phys. Rev. B {\bf 79}, 092506 (2009). We further extend this work here and consider the A$_2$ phase of superfluid…
The magnetic dipole-dipole interaction does not prevent existence of half-quantum vortices in the polar phase of superfluid He-3 which can be stable in uniaxial anisotropic aerogel. Here we discus this exotic possibility. After developing a…
One of the most sought-after objects in topological quantum matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid 3He-A, but have never been resolved there. Here we report…
We have found the precise stability region of the half quantum vortex (HQV) for superfluid $^3$He A phase confined in parallel plates with a narrow gap under rotation. Standard Ginzburg-Landau free energy, which is well established, is…
Unlike to superfluid $^4$He the superfluid $^3$He-A support the existence of vortices with half quantum of circulation as well as single quantum vortices. The singular single quanta vortices as well as nonsingular vortices with 2 quanta of…
NMR experiments on superfluid 3He in a nematic aerogel have shown that the stability of the half-quantum vortex (HQV) realized in the polar phase depends on the relative direction between the magnetic field and the anisotropy axis brought…
The polar phase of superfluid $^3$He is stable in "nematically ordered" densed aerogel. A rotating vessel with the polar superfluid can be filled either by an array of the single quantum vortices or by an array of the half-quantum vortices.…
The superfluid state in bulk liquid $^3$He is realized in the form of A or B phases. Uniaxially anisotropic aerogel (nafen) stabilizes transition from the normal to the polar superfluid state which on further cooling transitions to the…
NMR experiments on liquid $^3$He infused into uniaxially anisotropic silica aerogels show the stabilisation of two equal-spin-pairing chiral phases on cooling from the normal phase. The alignment of the chiral axis relative to the…
We demonstrate that the confinement of half-quantized vortices (HQVs) in coherently coupled Bose-Einstein condensates (BECs) simulates certain aspects of the confinement in $SU(2)$ quantum chromodynamics (QCD) in 2+1 space-time dimensions.…
$^3$He is an example of the system with non-trivial Cooper paring. A few different superfluid phases are known in this system. Recently the new one, the polar phase, have been observed in $^3$He confined in nematically ordered aerogel. A…
Half-quantum vortices (HQVs) can exist in a superconductor or superfluid with an exact or approximate U(1) \times U(1) symmetry, for instance in spinor condensates, 3He-A, Sr2RuO4, and possibly cuprate superconductors with stripe order. In…
Motivated by the recent observation and argument on a large half-quantum vortex (HQV) pair connencted by a Kibble wall in superfluid 3He in nematic aerogels, we numerically study to what extent a huge HQV pair can intrinsically occur with…
Recently new topological phase of superfluid $^3$He has been discovered -- the $\beta$ phase, which is obtained by strong polarization of the nematic polar phase. We consider half-quantum vortices, which are formed in rotating cryostat, and…
A rich variety of Fermi systems condense by forming bound pairs, including high temperature [1] and heavy fermion [2] superconductors, Sr2RuO4 [3], cold atomic gases [4], and superfluid 3He [5]. Some of these form exotic quantum states…
Superfluid $^3$He under nanoscale confinement has generated significant interest due to the rich spectrum of phases with complex order parameters that may be stabilized. Experiments have uncovered a variety of interesting phenomena, but a…
In the triplet equal-spin-pairing states of both 3He-A phase and Sr2RuO4 superconductor, existence of Half-Quantum Vortices HQVs are possible. The vortices carry half-integer multiples of magnetic quantum flux (hc/2e). To obtain equilibrium…