Draw half arrow

We can also design a new arrow style by use Graphics

arrowStyle = 
  Graphics[{Black, Polygon[{{0, 0}, {-1, .2}, {-.8, 0}, {0, 0}}]}];
semiArrow = Arrowheads[{{0.2, 1, arrowStyle}}];
Graphics[{semiArrow, Arrow[{{0, 0}, {1, 1}}], 
  Arrow[{{1 + .1, 1 - .1}, {.1, -.1}}]}]The above codes does not suitable for 3D,why not?

It is the first attempt. Late we can adjust the thickness of line and the position of arrow to get another style.

Update The above codes does not suitable for 3D,why not?

 Clear["`*"];
 arrowStyle = 
  Graphics[{Black, FaceForm[Red], 
    Polygon[{{0, 0}, {-1, .2}, {-.8, 0}, {0, 0}}], EdgeForm[], 
    FaceForm[], Polygon[{{0, 0}, {-1, -.2}, {-.8, 0}, {0, 0}}]}];
semiArrow = Arrowheads[{{0.2, 1, arrowStyle}}];
Graphics3D[{semiArrow, Arrow[{{0, 0, 0}, {1, 1, 1}}]}]

This looks like the unicode character "rightwards harpoon over leftwards harpoon", with code U+21cc. It can be found here. We might use it in Mathematica like this:

harpoon = FromCharacterCode@FromDigits["21cc", 16];

Graphics[{
  Text[Style[harpoon, FontSize -> 25], {0, 0}],
  Text[Style[harpoon, FontSize -> 25], {10, 5}],
  Rotate[
   Text[Style[harpoon, FontSize -> 25], {5, 5}],
   30 Degree
   ]
  }]

Other fonts might look more similar to your example.