Based on your desired output, I’m not sure if a sparse tensor is really what you are looking for, as it looks like you would just like to stack both tensors.
However, would this work for you:
t2 = torch.stack([t0,t1]) 
tensor(indices=tensor([[0, 0, 1, 1, 1],
                       [1, 2, 0, 1, 2]]),
       values=tensor([1., 2., 3., 4., 5.]),
       size=(2, 3), nnz=5, layout=torch.sparse_coo)